Path II - All the Webpath Q's

A 29 year old man is bothered by a "cold sore" on his upper lip. After a week, he notices the appearance of several rounded, slightly erythematous lesions on the palms of his hands averaging 0.4 to 0.8 cm in size. Each of the lesions has a targetoid appearance with a central dark red area. After a course of acyclovir, the lesions on his hands disappear. Which of the following conditions did he most likely have: A Erythema multiforme B Molluscum contagiosum C Keratoacanthoma D Impetigo E Pemphigus vulgaris

A Erythema multiforme

The worldwide increase in skin cancers has resulted primarily from increased exposure to: A Ultraviolet B (UVB) radiation B Gamma radiation C Nitrous oxides (NOx) D Ozone (O3) E Chlorofluorocarbons (CFC's)

A. Ultraviolet B (UVB) radiation

A 38-year-old woman has become increasingly fatigued for the past 3 months. During the past week she has noted purple blotches on her skin. On physical examination there are purpuric areas of skin on her trunk and extremities. She has no hepatosplenomegaly and no lymphadenopathy. Laboratory studies show Hgb 6.8 g/dL, Hct 20.7%, MCV 91 fL, platelet count 28,760/microliter, and WBC count 1940/microliter. Which of the following is the most likely diagnosis? A Aplastic anemia B Myeloproliferative disorder C Immune thrombocytopenic purpura D Large B cell lymphoma E Hereditary spherocytosis

A Aplastic anemia (A) CORRECT. There is evidence from the peripheral cytopenias for marked hypocellularity of the bone marrow with aplastic anemia. The spleen is of normal size with aplastic anemia. The 'aplasia' here refers to the three major cell lines: myeloid, and megakaryocytic as well as erythroid.

A 38-year-old man has had upper abdominal pain for 3 months. For the past week he has had nausea. On physical examination a stool sample is positive for occult blood. An upper GI endoscopy reveals no esophageal lesions, but there is a solitary 2 cm diameter shallow, sharply demarcated ulceration of the stomach. Which of the following is most characteristic for this lesion? A Antral location B Potential for metastases C Increased gastric acid production. D No need for biopsy E Accompanying pancreatic gastrinoma

A Antral location (A) CORRECT. The gastric antrum is the typical location for a benign peptic ulcer. The small size and sharp margins are characteristics for a benign ulcer, but all gastric ulcerations require biopsy because malignancies have many different appearances.

A 30-year-old woman has had mild fatigue for many years. Physical examination reveals a palpable spleen tip. Laboratory studies show Hgb 11.1 g/dL, Hct 28.8%, MCV 77 fL, platelet count 229,000/microliter, and WBC count 7340/microliter. Her reticulocyte count is 3.9%. Examination of her peripheral blood smear shows small RBCs that lack central pallor. Which of the following patterns of inheritance is most likely present with her disease? A Autosomal dominant, European ancestry B Autosomal recessive, Asian ancestry C X-linked recessive, Middle Eastern ancestry D Autosomal recessive, West African ancestry E Sporadic occurrence

A Autosomal dominant, European ancestry (A) CORRECT. Hereditary spherocytosis is the most common inherited hemolytic anemia in persons of northern European descent. It has a frequency in this population of 1 in 5000. An abnormality in the structural membrane proteins ankyrin or spectrin accounts for the abnormality.

A 76-year-old bedridden male admitted to the hospital from a nursing home is found to have a 2 cm diameter area of skin ulceration extending to underlying soft tissue over the sacral region. This is most likely a: A Decubitus ulcer B Superficial candida infection C Basal cell carcinoma D Tinea corporis infection E Herpes zoster infection

A Decubitus ulcer

A 52-year-old man has had a fever with cough for a month. On physical examination his temperature is 37.5°C. There are crackles auscultated in upper lung fields. A chest radiograph shows a reticulonodular pattern with upper lobe cavitary lesions. His sputum is positive for acid fast bacilli. A CBC shows: Hgb 14.2 g/dL, Hct 42.5%, MCV 92 fL, platelet count 225,000/uL, and WBC count 44,500/uL with differential count of 59 segs, 20 bands, 8 metas, 4 myelos, 2 promyelos, 5 lymphs, and 2 monos. Which of the following laboratory test findings is most likely to be present in this man? A High leukocyte alkaline phosphatase B Karyotype with 46, XY, t(9;22) C Monoclonal gammopathy D Elevated D-dimer E Positive TdT assay

A High leukocyte alkaline phosphatase (A) CORRECT. The findings point to a leukemoid reaction that can be seen with infections such as tuberculosis.

A 51-year-old man has become increasingly fatigued for the past 10 months. On physical examination there are no abnormal findings. Laboratory studies show his Hgb is 9.2, Hct 27.9%, MCV 132 fL, platelet count 242,000/microliter, and WBC count 7590/microliter. Which of the following morphologic findings is most likely to be present on examination of his peripheral blood smear? A Hypersegmented neutrophils B Nucleated red blood cells C Blasts with Auer rods D Hypochromic, microcytic RBC's E Schistocytes

A Hypersegmented neutrophils (A) CORRECT. The increased MCV points to a macrocytic anemia such as a megaloblastic anemia that can also have hypersegmented PMN's from delayed maturation and reduced numbers of nuclear divisions.

A 72-year-old Caucasian man has had increasing fatigue for the past year. On physical examination there are no abnormal findings. Laboratory studies show a Hgb of 9.1 gm/dL, Hct 27.9%, MCV 96 fL, WBC count 3700/microliter, and platelet count 125,000/microliter. The WBC differential count shows 53 segs, 5 bands, 2 metamyelocytes, 1 myelocyte, 32 lymphs, 7 monos, and 5 nucleated RBCs/100 WBCs. He has a negative direct and indirect Coombs test. Which of the following diseases is he most likely to have? A Metastatic carcinoma B Chronic alcoholism C Malabsorption D Hemoglobinopathy E Chronic blood loss F Systemic lupus erythematosus

A Metastatic carcinoma (A) CORRECT. Metastatic tumor involving marrow, or marrow fibrosis, is a 'myelophthisic' process that reduces normal hematopoiesis and leads to a peripheral 'leukoerythroblastic' picture with immature RBC's and WBC's in the peripheral blood, as seen here with nucleated RBCs and white cells even more immature than bands (metamyelocytes, myelocytes) on the smear.

A 45-year-old man has had increasing abdominal discomfort with abdominal enlargement for the past two years. On physical examination, the spleen can be felt below the left costal margin. There is no fluid wave. An abdominal CT scan reveals massive (estimated 3000 gm size) splenomegaly. Laboratory data include Hgb 9 g/dL, WBC count 5,000/microliter, and platelet count 50,000/microliter. Which of the following underlying conditions is he most likely to have? A Myelofibrosis B Sickle cell anemia C Portal hypertension D Infectious mononucleosis E Hemochromatosis

A Myelofibrosis (A) CORRECT. Myeloproliferative disorders, and myelofibrosis in particular, are known to cause massive splenomegaly. As hematopoiesis is reduced in the marrow, it moves elsewhere (extramedullary hematopoiesis) such as the spleen.

A 73-year-old woman has had increasing fatigue with a 3 kg weight loss over the past 7 months. Her hands become purple and painful upon exposure to cold. On physical examination she has a palpable spleen tip. Laboratory studies show Hgb 10.5 g/dL, Hct 31.7%, MCV 99 fL, platelet count 193,600/microliter, and WBC count 5390/microliter. The direct Coombs test is positive at 4°C and negative at 37°C. Which of the following underlying diseases is this woman most likely to have? A Non-Hodgkin lymphoma B Systemic lupus erythematosus C Pernicious anemia D Scleroderma E Thalassemia minor

A Non-Hodgkin lymphoma (A) CORRECT. She has a cold autoimmune hemolytic anemia. Though this may be idiopathic or due to an infection (Epstein-Barr virus; Mycoplasma) a malignant lymphoma must be considered. Since the RBC's are being sequestered in the spleen with extravascular hemolysis, there is splenomegaly. A warm autoimmune hemolytic anemia will often produce intravascular hemolysis with hemoglobinemia that will more often lead to renal failure. There will more often be jaundice with intravascular hemolysis. Intravascular hemolysis will decrease haptoglobin more.

A 72-year-old woman notes increasing jaundice and nausea for the past month. On physical examination she is afebrile, but scleral icterus is present. There is no abdominal pain on palpation. She has active bowel sounds. A stool sample is negative for occult blood. Laboratory findings include total protein 6.1 g/dL, albumin 3.3 g/dL, alkaline phosphatase 210 U/L, AST 49 U/L, ALT 40 U/L, total bilirubin 7.2 mg/dL, and direct bilirubin 6.3 mg/dL. Her serum lipase is 50 U/L. Which of the following conditions is she most likely to have? A Pancreatic adenocarcinoma B Cystic fibrosis C Chronic active hepatitis D Primary biliary cholangitis E Chronic persistent hepatitis F Autoimmune hemolytic anemia

A Pancreatic adenocarcinoma (A) CORRECT. Adenocarcinoma of the head of pancreas produces extrahepatic biliary obstruction with an elevation predominantly of the direct bilirubin along with an elevation in alkaline phosphatase. This results in the classic finding of 'painless jaundice'. There is no significant inflammatory component.

A 26-year-old male has pain when he sits down for any length of time. Examination reveals some small pitted areas in the skin at the tailbone above the anal cleft, beneath which is a 1 cm tender, soft mass. This is most probably a(an): A Pilonidal sinus and abscess B Carbuncle C Decubitus ulcer D Adnexal skin tumor E Bone spur

A Pilonidal sinus and abscess

A 15-year-old boy from Ghana has the acute onset of right upper quadrant abdominal pain. Abdominal ultrasound reveals a dilated gallbladder with thickened wall and filled with calculi. A laparoscopic cholecystectomy is performed. The gallbladder is opened to reveal ten multifaceted 0.5 to 1 cm diameter dark, greenish-black gallstones. Which of the following underlying conditions does this boy most likely have? A Sickle cell anemia B Crohn disease C Hypercholesterolemia D Hyperparathyroidism E Primary biliary cholangitis F Schistosomiasis

A Sickle cell anemia (A) CORRECT. Darkly pigmented gallstones usually contain bilirubin. Hyperbilirubinemia is a consequence of hemolysis. Patients with sickle cell anemia have chronic hemolysis.

A 41-year-old man has experienced progressive fatigue, pruritus, and icterus for the past 4 months. He had a total colectomy performed five years ago. On physical examination he is afebrile. Scleral icterus is present. His stool from a Koch pouch is negative for occult blood. Cholangiography reveals the widespread obliteration of intrahepatic bile ducts. A liver biopsy is performed and on microscopic examination shows periductular 'onion skin' fibrosis with a moderate lymphocytic infiltrate. Some intrahepatic bile ducts are obliterated, but there is no interface hepatitis. Which of the following underlying diseases is he most likely to have? A Ulcerative colitis B Systemic lupus erythematosus C Wilson disease D Hepatitis B viral infection E Primary biliary cholangitis F Alpha-1-antitrypsin deficiency

A Ulcerative colitis (A) CORRECT. Sclerosing cholangitis is one of the extra-intestinal manifestations of inflammatory bowel disease and is seen most frequently with ulcerative colitis. The colectomy was probably performed because of his increasing risk for adenocarcinoma, but even after colectomy extraintestinal manifestations of UC can occur.

An urticarial skin rash is most typical for which of the following patients: A A 17-year-old female with type I hypersensitivity to oysters B A 30-year-old male with systemic lupus erythematosus C A 26-year-old female who fell into a patch of poison ivy D A 48-year-old male with psoriasis E A 53-year-old female with progressive systemic sclerosis

A. A 17-year-old female with type I hypersensitivity to oysters

Which of the following statements regarding a burn injury is INCORRECT: A Epithelial regeneration cannot occur in a partial thickness burn without skin grafting. B Significant fluid loss may occur through burned skin. C Most fatalities from burn injuries in patients in hospital occur from sepsis. D A full thickness burn injury destroys the dermal appendages. E Elastic fibers destroyed by a burn injury are not regenerated.

A. Epithelial regeneration cannot occur in a partial thickness burn without skin grafting.

A 1.2 cm diameter condyloma acuminatum of the vulva of a 26 year old female has a soft, tan to white, cauliflower appearance. Which of the following situations is most likely to have contributed to the development of this lesion: A Human papillomavirus infection B Blood transfusion C Familial hypercholesterolemia D Sunbathing E Treponema pallidum infection

A. Human papillomavirus infection

A 25 year old male has multiple firm nodules, some of which are up to several centimeters in size, that are disfiguring because they are located on his hands and arms. Also noted on physical examination are scattered light brown macules with smooth borders, averaging about 2 to 3 centimeters in size, over the skin of his trunk and arms. These lesions are most likely to represent: A Neurofibromatosis B Kaposi's sarcoma C Nevi D Actinic keratoses E Impetigo

A. Neurofibromatosis

A 30-year-old man has had a progressively worsening productive cough for one month. On physical examination, a few small non-tender lymph nodes are palpable in the axillae, and the tip of the spleen is palpable. Laboratory studies show Hgb 10.2 g/dL, Hct 31.1%, MCV 90 fL, WBC count 67,000/microliter, and platelet count 36,000/microliter. Microscopic examination of his peripheral blood smear shows many blasts with Auer rods. Which of the following is the most likely diagnosis? A Leukemoid reaction B Acute myelogenous leukemia C Chronic lymphocytic leukemia D Lymphoblastic leukemia E Leukoerythroblastosis

B Acute myelogenous leukemia (B) CORRECT. The high WBC count with the blasts and Auer rods are very characteristic for an acute myelogenous leukemia (AML) that can occur in young adults.

A 19-year-old primigravida of Southeast Asian ancestry gives birth at 35 weeks gestation a male infant. On physical examination the infant is markedly hydropic. Laboratory studies show his hematocrit is 17% and the peripheral blood smear reveals numerous nucleated red blood cells and even a few erythroblasts. The red blood cells display marked anisocytosis and poikilocytosis. Which of the following diseases is most likely to be present in this infant? A Sickle cell anemia B Alpha-thalassemia C Hemoglobin E disease D G6PD deficiency E Hereditary elliptocytosis

B Alpha-thalassemia (B) CORRECT. The form of alpha-thalassemia seen in Southeast Asia has two abnormal alpha globin genes on the same chromosome, so it is possible to inherit two bad sets, leading to a complete lack of alpha globin chain formation, so that fetal hemoglobin (two alpha and two gamma chains) cannot be made, and there is a severe anemia.

A 31-year-old man with a stab wound to the abdomen is taken to surgery. While repairing the small intestine, the surgeon notices the presence of a 1 cm circumscribed submucosal mass in the ileum. The lesion is resected and on gross examination has a firm, yellow-tan cut surface. Microscopically, the mass is composed of nests of cells with uniform small round nuclei and cytoplasm with small purple granules. The cytoplasm is positive with antibody to chromogranin on immunohistochemical staining. Which of the following pathologic findings is most likely to accompany this man's lesion? A Liver metastases B Another similar lesion C Multiple gastric ulcerations D Pancreatic adenocarcinoma E Inflammatory bowel disease F Tropheryma whippelii infection

B Another similar lesion (B) CORRECT. This lesion is a carcinoid tumor, and these neoplasms can be multiple, even when biologically benign. Small carcinoids typically act in a benign fashion. Most of them do not secrete hormones causing clinical symptoms, but some do. They are often incidental findings.

A 51-year-old male from the Everglades of Florida who has lived by himself for many years finally came to a physician when, after losing the vision in one eye due to a large infiltrating neoplasm that started on his right eyelid, the neoplasm was beginning to destroy the other eye. This neoplasm is probably a: A Malignant melanoma B Basal cell carcinoma C Keratoacanthoma D Hemangioma E Kaposi's sarcoma

B Basal cell carcinoma

A 16-year-old boy has had a low energy level for as long as he can remember. On physical examination he has a palpable spleen tip. A CBC shows Hgb of 8.8 g/dL, Hct 24.1%, MCV 65 fL, platelet count 187,000/microliter, and WBC count 7400/microliter. His serum ferritin is 3740 ng/mL. A bone marrow biopsy is performed and on microscopic examination reveals a myeloid:erythroid ratio of 1:4, and there is 4+ stainable iron. Which of the following is the most likely diagnosis? A G6PD deficiency B Beta-thalassemia C Sickle cell anemia D Hereditary spherocytosis E Malaria

B Beta-thalassemia (B) CORRECT. Reduced beta-globin chain synthesis from beta-thalassemia leads to RBC microcytosis, hypochromia, ineffective erythropoiesis, and excessive iron absorption. There is chronic anemia, because the major hemoglobin A1 is produced insufficiently. The nature of the mutation, typically affecting RNA transcript production, determines the severity of the disease.

A 41-year-old man has a history of drinking 1 to 2 liters of whisky per day for the past 20 years. He has had numerous episodes of nausea and vomiting in the past 5 years. He now experiences a bout of prolonged vomiting, followed by massive hematemesis. On physical examination his vital signs are: T 36.9°C, P 110/min, RR 26/min, and BP 80/40 mm Hg lying down. His heart has a regular rate and rhythm with no murmurs and his lungs are clear to auscultation. There is no abdominal tenderness or distension and bowel sounds are present. His stool is negative for occult blood. Which of the following is the most likely diagnosis? A Hiatal hernia B Esophageal laceration C Esophageal pulsion diverticulum D Barrett esophagus E Esophageal squamous cell carcinoma F Esophageal stricture

B Esophageal laceration (B) CORRECT. This is Mallory-Weiss syndrome. The lacerations are induced by the forceful, prolonged vomiting and can extend to submucosal veins that bleed profusely. Esophageal variceal bleeding should also be suspected with such a history, because hepatic cirrhosis is likely to be present. The acute nature of the process means blood has not yet passed through the bowel to the rectum.

A 28-year-old woman with recent onset of a major depressive disorder ingests an entire bottle (100 capsules, 500 mg each) of a medication containing acetaminophen. She becomes progressively obtunded over the next 8 hours. Which of the following microscopic findings is most likely to be present in her liver 3 days following this ingestion? A Normal histology B Extensive necrosis C Bridging fibrosis D Severe steatosis E Portal chronic inflammation F Intracanalicular cholestasis

B Extensive necrosis (B) CORRECT. This is a massive overdose of acetaminophen, which causes extensive hepatic necrosis. Administration of N-acetylcysteine helps increase glutathione to counter the toxicity.

Queensland, Australia has a very sunny climate and is populated by people of mostly northern European ancestry. One health policy sponsored by the state government is aimed at getting people to wear: A Shoes B Eyeglasses C Hats D Condoms E Swimsuits

B Eyeglasses

A 69-year-old man has noted the presence of several lumps on the right side of his neck for the past 5 months. On physical examination he has firm, non-tender, movable lymph nodes palpable in right posterior cervical region. He does not have splenomegaly or hepatomegaly. Laboratory studies show Hgb 11.3 g/dL, Hct 40%, MCV 87 fL, platelet count 256,000/microliter, and WBC count 7230/microliter. A cervical lymph node biopsy is performed and on microscopic examination shows numerous crowded nodules of small, monomorphic lymphocytes. Which of the following is the most likely diagnosis? A Chronic lymphocytic leukemia B Follicular lymphoma C Infectious mononucleosis D Hodgkin lymphoma, lymphocyte predominance type E Reactive hyperplasia

B Follicular lymphoma (B) CORRECT. Lymphadenopathy with malignant lymphoma is typically nontender, as contrasted with the lymphadenopathy of infections. Follicular lymphomas occur in adults.

A 17-year-old adolescent has had malaise for the past 3 weeks. He has a mild pharyngitis on physical examination, as well as tender axillary and inguinal lymphadenopathy. The spleen is palpable. A CBC shows Hgb 14.0 g/dL, Hct 42.2%, MCV 90 fL, platelet count 301,300/microliter, and WBC count 8120/microliter with 'atypical lymphocytes' on the peripheral blood smear. His illness is most likely to be acquired via which of the following mechanisms? A congenital genetic abnormality B From close contact on a date C As a result of an insect bite D Through an environmental exposure at work E Without any known etiology

B From close contact on a date (B) CORRECT. Infectious mononucleosis with Epstein-Barr virus (EBV) infection is typically acquired with close personal contact. This self-limited viral infection resolves in weeks.

A 50-year-old man has had persistent nausea for 5 years with occasional vomiting. On physical examination there are no abnormal findings. He undergoes upper GI endoscopy, and a small area of gastric fundal mucosa has loss of rugal folds. Biopsies are taken and microscopically reveal well-differentiated adenocarcinoma confined to the mucosa. An upper GI endoscopy performed 5 years previously showed a pattern of gastritis and microscopically there was chronic inflammation with the presence of. Which of the following is the most likely risk factor for his neoplasm? A Inherited APC gene mutation B Helicobacter pylori infection C Chronic alcohol abuse D Use of non-steroidal anti-inflammatory drugs E Vitamin B12 deficiency

B Helicobacter pylori infection (B) CORRECT. H. pylori infection can lead to chronic gastritis that promotes development of adenocarcinoma. The prognosis with early gastric carcinoma (EGC) is good, compared with other gastric cancers.

A 68-year-old man has had malaise for the past year. On physical examination, there are no abnormal findings. His Hgb is 10.5 g/dL, Hct 31.5%, MCV 88 fL, platelet count 211,000/microliter, and WBC count 6980/microliter. His total serum iron is 130 microgm/dL total iron binding capacity (TIBC) 230 microgm/dL, and soluble serum transferrin receptor is normal. A bone marrow biopsy is performed and microscopic examination shows that maturation is occurring in all cell lines and there are no abnormal cells seen. Stainable iron in the bone marrow is increased. Which of the following underlying diseases is he most likely to have? A Diverticulosis B Hepatitis C infection C Systemic lupus erythematosus D Atrophic gastritis E Fanconi anemia

B Hepatitis C infection (B) CORRECT. He has findings of anemia of chronic disease, with a high (or normal) % iron saturation, increased iron stores, and normal soluble serum transferrin receptor. In iron deficiency, iron stores are diminished, % saturation decreased, and soluble serum transferrin receptor increased. Hepatitis C viral infection is a chronic disease.

A 65 year old male has been undergoing chemotherapy for treatment of a small cell anaplastic carcinoma of the right lung. He has been bothered for several weeks by an outbreak of pruritic lesions in a 2 X 14 cm area along the right trunk. The lesions are clear vesicles, some of which have become secondarily infected after rupture from scratching. The most likely diagnosis is: A Kaposi's sarcoma B Herpes zoster C Neurofibromatosis D Acne E Impetigo

B Herpes zoster

A 33-year-old woman has experienced low grade fevers, night sweats, and generalized malaise for the past 2 months. On physical examination she has non-tender cervical and supraclavicular lymphadenopathy. A cervical lymph node biopsy is performed. On microscopic examination at high magnification there are occasional CD15+ and CD30+ Reed-Sternberg cells along with large and small lymphocytes and bands of fibrosis. Which of the following is the most likely diagnosis? A Burkitt lymphoma B Hodgkin lymphoma C Cat scratch disease D Mycosis fungoides E Multiple myeloma

B Hodgkin lymphoma (B) CORRECT. Reed-Sternberg cells are multinucleated with large nucleoli. Variants of them called lacunar cells are also seen with some forms of Hodgkin lymphoma. Her 2 lymph node groups on one side of the diaphragm put this at stage II, but the prognosis is still good.

A dome-shaped, flesh-colored nodule is present on the cheek of a 55-year-old male. While waiting several months for a referral in his managed care health plan, the lesion disappears. It is most likely a (an): A Skin tag B Keratoacanthoma C Dermatofibroma D Epidermal inclusion cyst E Hemangioma

B Keratoacanthoma

A 39-year-old male has a slightly raised, pigmented lesion on the chest which has recently become darker with irregular borders present. It has enlarged from 1 cm to 1.5 cm. These findings should suggest that this lesion is a(an): A Lentigo nevus B Malignant melanoma C Intradermal nevus D Hemangioma E Basal cell carcinoma

B Malignant melanoma

A 44-year-old man has noted a change in the appearance of his face over the past 7 months. On physical examination his facial skin is thickened and reddened. A punch biopsy of skin is performed and on microscopic examination shows infiltration by neoplastic T lymphocytes that are CD4 positive. Which of the following is the most likely diagnosis? A Hodgkin lymphoma B Mycosis fungoides C Burkitt lymphoma D Acute lymphocytic leukemia E Hairy cell leukemia

B Mycosis fungoides (B) CORRECT. Mycosis fungoides (with no relationship to fungi) is one form of cutaneous T-cell lymphoma. The abnormal CD4 cell proliferation is infiltrting the skin and producing erythroderma. If these neoplastic cells circulate, it is known as Sezary syndrome.

A 42-year-old woman has noticed during the past month that even minor bumps produce major bruises over her body. On physical examination she has areas of purpura on the skin of her arms and legs. She is afebrile. Laboratory studies shows her prothrombin time is 12.9 seconds (control 13 sec) and partial thromboplastin time 26.2 seconds (control 25 sec). Her CBC shows a Hgb of 11.1 g/dL, Hct 33.1%, MCV 84 fL, platelet count 790,000/uL, and WBC count 45,400/uL. A bone marrow biopsy is performed and on microscopic examination shows hypercellularity with myeloid and megakaryocytic hyperplasia. Which of the following is the most likely diagnosis? A Epstein-Barr virus infection B Myeloproliferative disorder C Drug reaction to recent antibiotic therapy D Wiskott-Aldrich syndrome E Megaloblastic anemia

B Myeloproliferative disorder (B) CORRECT. There is an increase in numbers of more than one cell line in the marrow. Paradoxically, there is bleeding because the platelets are functionally abnormal, even though there are lots of them.

A 29-year-old woman has the sudden onset of fever, abdominal pain, tachycardia, and nausea. On physical examination her vital signs include T 37.6°C, P 90/minute, RR 18/minute, and BP 100/60 mm Hg. Her conjunctivae are icteric. The spleen tip is palpable. Laboratory studies shows Hgb 9.0 g/dL, Hct 27.3%, MCV 99 fL, platelet count 209,500/microliter, and WBC count 6840/microliter. Her reticulocyte count is 0.1%. On microscopic examination of her peripheral blood smear, the RBC's are small and lack central pallor. Which of the following most likely initiated this woman's acute illness? A Quinacrine use B Parvovirus infection C Decreased oxygen tension D Exposure to cold E Transfusion therapy

B Parvovirus infection (B) CORRECT. The findings point to hereditary spherocytosis. Parvovirus B19 infects erythroid precursors and can lead to an aplastic crisis in persons with hemoglobinopathies. The hemoglobinopathy impairs the marrow ability to respond to the stress of the acute infection.

A 44-year-old man, an emergency medical technician, has felt fatigued for the past 4 months. He experienced an episode of jaundice 10 years ago, but that resolved and he has been healthy since. On physical examination there are no remarkable findings. Laboratory studies show his hemoglobin is 14 g/dL and serum electrolytes normal, but he has a total protein of 5.4 g/dL, albumin 2.9 g/dL, ALT 132 U/L and AST 113 U/L with total bilirubin 1.3 mg/dL and direct bilirubin 0.8 mg/dL. A liver biopsy is performed and microscopic examination shows interface inflammation with extension of inflammation into the lobules from the triads. There is focal ballooning degeneration of hepatocytes. Which of the following laboratory test findings is most characteristic for his disease? A Decreased serum alpha-1-antitrypsin B Positive hepatitis B surface antigen C Increased serum ferritin D Decreased serum ceruloplasmin E Positive antimitochondrial antibody

B Positive hepatitis B surface antigen (B) CORRECT. This is chronic active hepatitis with hepatitis B infection. This illustrates the wisdom of getting the series of hepatitis B vaccinations. Though most persons clear the virus, a significant number go on to chronic liver disease.

A 28-year-old African-American woman has had worsening fatigue for the past 2 months. On physical examination she has an erythematous macular rash on her upper chest, forearms, and face. Laboratory studies show Hgb 9.2 g/dL, Hct 27.9%, MCV 101 fL, platelet count 179,000/microliter, and WBC count 5850/microliter. The red blood cell distribution width is markedly increased. Her peripheral blood smear shows polychromasia. Her reticulocyte count is 4.2%. The serum haptoglobin is 3 mg/dL. Serum chemistries show total protein 7.9 g/dL, albumin 3.8 g/dL, alkaline phosphatase 49 U/L, AST 81 U/L, ALT 27 U/L, total bilirubin 3.3 mg/dL, and direct bilirubin 0.8 mg/dL. Hemoglobinuria is detected on urinalysis. Which of the following underlying conditions is she most likely to have? A Multiple myeloma B Systemic lupus erythematosus C Hepatitis C infection D Hereditary spherocytosis E Vitamin B12 deficiency

B Systemic lupus erythematosus (B) CORRECT. These findings all point to intravascular hemolysis that can be seen with warm autoimmune hemolytic anemia that can complicate autoimmune diseases such as SLE. Her reticulocytosis is the response to the hemolysis and accounts for the mild increase in MCV.

The appearance of grouped vesicles in a dermatomal distribution on the skin is most likely to be found in which of the following patients: A A 59 year old male with a long history of sun exposure B A 35 year old male with HIV infection C A 19 year old female with acne D A 41 year old male with neurofibromatosis E A 5 year old child with Staphylococcus aureus infection

B. A 35 year old male with HIV infection

A 5-year-old boy has become increasingly lethargic for the past 2 months. On physical examination his temperature is 37.3°C. There are ecchymoses noted on the skin of his lower legs. Laboratory studies show Hgb 9.2 g/dL, Hct 27.8%, MCV 91 fL, platelet count 101,000/microliter, and WBC count 12,128/microliter. A bone marrow biopsy is performed and on microscopic examination shows nearly 100% cellularity with replacement by primitive cells that have large nuclei with delicate chromatin and indistinct nucleoli with scanty cytoplasm. These cells mark for CD10 (CALLA) antigen. Which of the following is the most likely diagnosis? A Acute myeloid leukemia B Hodgkin lymphoma C Acute lymphoblastic leukemia D Epstein-Barr virus infection E Chronic myelogenous leukemia F Chronic lymphocytic leukemia

C Acute lymphoblastic leukemia (C) CORRECT. He has ALL, which typically occurs in children. The CALLA variety is common and responds well to therapy.

Tinea pedis is a superficial fungal infection known as: A Impetigo B A cold sore C Athlete's foot D Ringworm E Jock itch

C Athlete's foot

A 58-year-old man has had increasing difficulty swallowing for the past 6 months and has lost 5 kg. No abnormal physical examination findings are noted. Upper GI endoscopy reveals a nearly circumferential mass with overlying ulceration in the mid esophageal region. Biopsy of the mass reveals pink polygonal cells with marked hyperchromatism and pleomorphism. Which of the following is the most likely risk factor for development of his disease? A Iron deficiency B Helicobacter pylori infection C Chronic alcohol abuse D High fruit diet E Zenker diverticulum

C Chronic alcohol abuse (C) CORRECT. Chronic alcoholism and tobacco use are two of the most important risk factors for squamous cell carcinoma of the esophagus in the U.S., specifically related to squamous cell carcinomas of the mid-esophagus, as in this man. Zinc and molybdenum are trace elements in the diet whose absence increases the risk for carcinoma of the esophagus. Food contaminated with Aspergillus also carries a risk, as does food containing nitrosamines.

A 35-year-old healthy woman develops sudden severe abdominal pain. On physical examination she is afebrile. On palpation the pain is centered in the mid-epigastric region, though there is marked diffuse tenderness in all quadrants. Bowel sounds are absent. No masses are palpable. Laboratory studies show her serum lipase is 610 U/L. Which of the following laboratory test findings is most likely to indicate the risk factor for this woman's illness? A Hypercholesterolemia B Positive urea breath test C Hypercalcemia D Elevated sweat chloride E Positive serology for HBsAg

C Hypercalcemia (C) CORRECT. Hypercalcemia is a less common cause for acute pancreatitis, though it can be found in persons with primary hyperparathyroidism. Once the pancreatitis has started, the formation of the chalky soap deposits of fat necrosis may draw off calcium to produce hypocalcemia.

A 43-year-old Caucasian male has over 150 pigmented nevi, predominantly on the trunk and upper extremities. Most are less than 6 mm in diameter, but some are over 1 cm and have various shades of brown. There is a family history of melanoma. He probably has: A Melanoma with metastases B No increased risk for melanoma C Dysplastic nevus syndrome D A history of extensive sun exposure E Arsenic poisoning

C Dysplastic nevus syndrome

A 10-year-old girl is noted to have increasing facial distortion for the past 8 months from a lesion involving her jaw. On physical examination she has a right mandibular mass. A biopsy is performed and on microscopic examination reveals a monotonous pattern of small non-cleaved lymphocytes. Cytogenetic analysis of these cells shows t(8;14). Infection with which of the following organisms is most likely to be associated with development of this girl's mass lesion? A Adenovirus B Cytomegalovirus C Epstein-Barr virus D Hepatitis C virus E Herpes simplex virus F HIV G HTLV-1

C Epstein-Barr virus (C) CORRECT. Burkitt lymphoma is endemic in Africa, mainly seen in children and young adults, and EBV infection is implicated in the pathogenesis of this B-cell lymphoma. Although Burkitt lymphoma is one of the fastest growing neoplasms, half of cases do respond to chemotherapy with long-term survival.

Two teenage siblings in the same family are noted to have frequent nosebleeds and easy bruising from even minor trauma. Both have had menorrhagia since menarche. One girl's CBC shows Hgb 14 g/dL, Hct 42.3%, MCV 90 fL, platelet count 242,000/microliter, and WBC count 7720/microliter. Her prothrombin time is 12 seconds and partial thromboplastin time 25 seconds. Platelet function studies show decreased aggregation in response to ADP, collagen, epinephrine, and thrombin. Which of the following disorders are these siblings most likely to have? A Hemophilia A B Antithrombin III deficiency C Glanzmann thrombasthenia D Systemic lupus erythematosus E Von Willebrand disease

C Glanzmann thrombasthenia (C) CORRECT. Glanzmann thrombasthenia is an autosomal recessive disorder from abnormalities in platelet glycoprotein IIb or IIIa, which form a receptor that is required for platelet aggregation, for uptake of fibrinogen into platelets, and clot retraction. This is a qualitative platelet defect; there are normal numbers of circulating platelets.

A 30-year-old man has had a sore throat with fever for 5 days. On physical examination he has mildly tender generalized cervical lymphadenopathy. Laboratory findings include Hgb 13 g/dL, platelet count 277,000/microliter, and WBC count 12,670/microliter with differential count of 75 segs, 10 bands, and 15 lymphs Which of the following is the most likely diagnosis? A Lymphocytic lymphoma B Hodgkin lymphoma C Group A Streptococcus infection D Human immunodeficiency virus infection E Brucellosis

C Group A Streptococcus infection (C) CORRECT. This is a typical history for infection with reactive lymphadenopathy. The microscopic findings in the node would include prominent germinal centers in follicles with a diffuse polyclonal hyperplasia composed of lymphocytes, plasma cells, and macrophages. The leukocytosis with left shift suggest bacterial infection.

A 49-year-old man has had increasing fatigue for the past 4 months. On physical examination he has massive splenomegaly but no lymphadenopathy. Laboratory studies show a Hgb of 10.1 g/dL, Hct 30.3%, MCV 90 fL, WBC count 1600/microliter, and platelet count 48,000/microliter. Examination of his peripheral blood smear shows increased numbers of peripheral blood lymphocytes containing tartrate-resistant acid phosphatase. Which of the following is the most likely diagnosis? A Chronic lymphocytic leukemia B HTLV-1 infection with leukemia C Hairy cell leukemia D Gaucher disease E Myelodysplasia

C Hairy cell leukemia (C) CORRECT. The name comes from characteristic cytoplasmic projections on the abnormal cells seen on the peripheral blood smear. This proliferation of B-lymphocytes involves peripheral blood, bone marrow, and spleen. Splenomegaly is often present, but hepatomegaly is not common, and lymphadenopathy is rare with hairy cell leukemia.

A 45-year-old man has had vague abdominal pain and nausea for the past 3 years. This pain is unrelieved by antacid medications. He has no difficulty swallowing and no heartburn following meals. On physical examination there are no abnormal findings. Upper GI endoscopy reveals antral mucosal erythema, but no ulcerations or masses. Biopsies are taken, and microscopically there is a chronic non-specific gastritis. Which of the following conditions is most likely to be present in this man? A Zollinger-Ellison syndrome B Pernicious anemia C Helicobacter pylori infection D Adenocarcinoma E Crohn disease F Mixed connective tissue disease

C Helicobacter pylori infection (C) CORRECT. H. pylori infection is often seen in association with chronic gastritis and with peptic ulcer disease.

A 72-year-old man has been feeling tired for the past 8 months. On physical examination there are no abnormal findings. Laboratory studies show Hgb 10.4 g/dL, Hct 30.3%, MCV 72 fL, platelet count 239,000/uL, and WBC count 7500/uL with automated differential count of 70.1% grans, 18.8% lymphs, and 11.1% monos. His total bilirubin is 1.0 mg/dL. Which of the following morphologic findings is most likely to be seen on his peripheral blood smear? A Fragmentation B Many nucleated forms C Hypochromasia D Spherocytosis E Howell-Jolly bodies

C Hypochromasia (C) CORRECT. The most probable cause of a hypochromic, microcytic anemia in an older man is iron deficiency anemia.

A 39-year-old man is having a routine physical examination because of a history of colon cancer in his family. He has no abdominal tenderness or masses, and active bowel sounds are present. However, his stool is positive for occult blood. Colonoscopy is performed. There are 7 polyps found in the ascending colon: three of these are small 0.5 cm pedunculated tubular adenomas, three are 1 cm tubulovillous adenomas, and one is a 2 cm sessile villous adenoma in the cecum containing a focus of well differentiated adenocarcinoma. Which of the following is his most likely underlying diagnosis? A PTEN-associated syndrome B Chronic ulcerative colitis C Hereditary non-polyposis colon carcinoma D Adenomatous polyposis coli E Peutz-Jehgers syndrome

C Hereditary non-polyposis colon carcinoma (C) CORRECT. The number of polyps is not great in this case, but a cancer at his age suggests an aggressive course for a polyp. Many polyps and cancers of HNPCC involve the right (ascending) colon. This condition arises from abnormal mismatch repair genes and accounts for perhaps 1 to 3% of all colon cancers.

A 37-year-old man known to be infected with HIV for the past 10 years has had abdominal pain for the past 3 days. Physical examination reveals abdominal distension with diffuse tenderness and absent bowel sounds. An abdominal CT scan reveals a mass lesion involving the small intestine. He is taken to surgery, and an area of bowel obstruction in the ileum is removed. Gross examination of the specimen shows a near-encircling firm white mass 10 cm long and 3 cm in greatest depth that infiltrates through the wall of the bowel. Which of the following neoplasms is this man most likely to have? A Plasmacytoma B Hodgkin lymphoma, lymphocyte predominant type C High-grade B cell lymphoma D Metastatic adenocarcinoma E Myeloproliferative disorder F Adenocarcinoma

C High-grade B cell lymphoma (C) CORRECT. Such lymphomas are typical for, as well as diagnostic of, AIDS in the setting of HIV infection. Extranodal involvement is common.

A 39 year old male with a previous diagnosis of cytomegalovirus (CMV) retinitis has noted the appearance of several reddish-purple plaques on his face and right hand. Biopsy reveals that the lesions are composed of a dermal proliferation of atypical spindle cells lining slit-like vascular spaces with extravasated red blood cells. These lesions most likely represent: A CMV infection B Keratoacanthomas C Kaposi's sarcoma D Acne E Tinea versicolor

C Kaposi's sarcoma

Which of the following statements regarding a nevus or nevi found on the skin of a 32-year-old male is INCORRECT: A Nevus cells are a morphologic variant of melanocytes. B Some nevi may not be pigmented. C Most melanomas arise from nevi. D Nevi evolve from junctional to compound to intradermal lesions. E Most Caucasians have at least one nevus.

C Most melanomas arise from nevi.

A 48-year-old man has experienced increasing malaise and difficulty concentrating at work for the past 6 months. On physical examination he has splenomegaly but no lymphadenopathy. He is afebrile. Laboratory studies show Hgb 12.0 g/dL, Hct 35.8%, MCV 92 fL, platelet count 390,000/uL, and WBC count 190,000/uL with differential count 73 segs, 12 bands, 6 metamyelocytes, 2 myelocytes, 2 myeloblasts, and 5 lymphs. The leukocyte alkaline phosphatase (LAP) score is very low. A bone marrow biopsy is performed. Which of the following microscopic findings is most likely to be found in this biopsy? A Sheets of plasma cells B Atypical cytokeratin positive glands C Numerous mature and immature myeloid cells D Predominance of adipocytes E Granulomas that have many acid fast bacilli

C Numerous mature and immature myeloid cells (C) CORRECT. He has chronic myelogenous leukemia (CML) which is a form of chronic myeloproliferative process in which one or more cell lines (myeloid, erythroid, megakaryocytic) becomes increased. This is usually driven by an acquired cytogenetic abnormality in a stem cell line, a t(9;22) that forms a BCR-ABL fusion gene with tyrosine kinase activation. Unlike acute myelogenous leukemia, blasts are uncommon in CML.

A 43-year-old man has had mid epigastric pain and nausea for the past 2 months. On physical examination he has no abnormal findings. On upper GI endoscopy a solitary sharply demarcated 2-cm shallow gastric antral ulcer is seen. Which of the following laboratory test findings is most likely to be present in this man? A Gastric achlorhydria B Positive serology for antinuclear antibody C Positive urea breath test D Increased plasma cortisol E Elevated serum gastrin

C Positive urea breath test (C) CORRECT. Helicobacter pylori organisms in the gastric mucus produce urease which will break down urea to ammonia and to CO2. For this urea breath test the patient drinks a measured quantity of a urea-containing solution with radiolabeled carbon. If the H. pylori organisms are present they metabolize the urea and release the radiolabeled carbon which is detected in exhaled air. Most gastric ulcers of this size are benign. Bleeding is a common complication of ulcer disease, seen in 25 to 33% of cases.

A 10 year old child complains of intense itching of his hands. Physical examination reveals several linear gray-brown lesions a few millimeters in length that appear in the skin between his fingers. Some of these lesions have been excoriated by scratching. The etiologic agent for these lesions is most likely to be: A Papillomavirus B Herpes zoster C Sarcoptes scabiei D Staphylococcus aureus E Tinea corporis

C Sarcoptes scabiei

A 32-year-old woman has a 10 year history of intermittent, bloody diarrhea. She has no other major medical problems. On physical examination there are no lesions palpable on digital rectal examination, but a stool sample is positive for occult blood. Colonoscopy reveals a friable, erythematous mucosa with focal ulceration that extends from the rectum to the mid-transverse colon. Biopsies are taken and all reveal mucosal acute and chronic inflammation with crypt distortion, occasional crypt abscesses, and superficial mucosal ulceration. This patient is at greatest risk for development of which of the following conditions? A Acute pancreatitis B Diverticulitis C Sclerosing cholangitis D Appendicitis E Perirectal fistula F Non-Hodgkin lymphoma

C Sclerosing cholangitis (C) CORRECT. This patient has ulcerative colitis (UC). One of the extraintestinal manifestations of this form of inflammatory bowel disease is hepatic sclerosing cholangitis, which can still occur even after the colon is removed.

An elderly male with no underlying medical conditions has several slowly enlarging, coin-like, lightly pigmented, velvety-surfaced lesions on the face and upper chest. These lesions have been present for many years. They are not painful and do not bleed when rubbed. These lesions most likely represent: A Intradermal nevi B Epidermal inclusion cysts C Seborrheic keratoses D Impetigo E Actinic keratoses

C Seborrheic keratoses

A 40-year-old woman has had a week long course of fever and mental confusion. Physical examination shows T 38.2°C, P 100/minute, RR 22/minute, and BP 100/60 mm Hg. She has widespread petechiae of skin and mucosal surfaces. Laboratory studies show her serum urea nitrogen is 52 mg/dL with creatinine 5.3 mg/dL. She has a hemoglobin of 12.2 g/dL, hematocrit 36.8%, MCV 93 fL, platelet count 19,000/microliter, and WBC count 8180/microliter. Schistocytes are seen on her peripheral blood smear. Her prothrombin time, partial thromboplastin time, and D-dimer are not elevated. Which of the following is the most likely diagnosis? A Disseminated intravascular coagulopathy B Idiopathic thrombocytopenic purpura C Thrombotic thrombocytopenic purpura D Trousseau syndrome E Warm autoimmune hemolytic anemia

C Thrombotic thrombocytopenic purpura (C) CORRECT. The pentad of fever, mental changes, renal failure, thrombocytopenia, and microangiopathic hemolytic anemia is characteristic of TTP. Platelets are activated directly, and not the coagulation system as a whole, so that the prothrombin time, partial thromboplastin time, and D-dimer are either not elevated or minimally elevated. The platelet activation leads to formation of hyaline thrombi in small arteries that promotes tissue ischemia in organs such as brain, with consequent neurologic impairment. Platelet transfusion is contraindicated.

A 25-year-old female has an erythematous malar skin rash along with a positive anti-nuclear antibody (ANA) test with a titer of 1:256 and anti-double stranded DNA titer of 1:256. Immunofluorescence staining performed on a biopsy of normal skin reveals band-like deposition of IgG and C3 at the dermal-epidermal junction. This is most typical for: A Polymyositis-dermatomyositis B Discoid lupus erythematosus (DLE) C Progressive systemic sclerosis (PSS) D Systemic lupus erythematosus (SLE) E Graft versus host disease (GVHD)

D Systemic lupus erythematosus (SLE)

A 20-year-old man is healthy but has a family history of colon cancer with onset at a young age. There are no abnormal physical examination findings. He undergoes colonoscopy and there are over 200 tubular adenomas ranging in size from 0.2 to 1 cm on gross inspection and microscopic examination of biopsies. Which of the following genetic diseases is he most likely to have? A Hereditary non-polyposis colon carcinoma syndrome B PTEN-associated syndrome C Peutz-Jeghers syndrome D Adenomatous polyposis coli E Multiple endocrine neoplasia

D Adenomatous polyposis coli (D) CORRECT. Persons with familial polyposis caused by inheritance of an abnormal APC gene should have a total colectomy for this reason. By late childhood to young adulthood, one or more of the polyps will give rise to adenocarcinoma. The polyps do not occur elsewhere in the GI tract.

A 42-year-old man has had multiple episodes of painful red nodules on his skin from dermal venous thrombosis, as well as abdominal pain from mesenteric vein thrombosis over the past year. He notes passing darker urine. Laboratory studies show Hgb 9.4 g/dL, Hct 29.2%, MCV 100 fL, platelet count 215,000/microliter, and WBC count of 8800/microliter. His RBCs show increased sensitivity to complement lysis. Flow cytometry is most likely to show reduction in which of the following markers on his RBCs? A CD4 B CD19 C CD33 D CD55 E CD68

D CD55 (D) CORRECT. He has paroxysmal nocturnal hemoglobinuria (PNH) an acquired stem cell disorder from mutation in the PIGA gene that renders RBCs very sensitive to complement lysis, as well as thrombosis in unusual veins. There is also risk for leukemia. The RBC markers CD55 and CD59 are reduced with PNH.

A 47-year-old man has been chronically fatigued for the past year. A physical examination yields no abnormal findings. A CBC shows: Hgb 10.8 g/dL, Hct 33.1%, MCV 104 fL, platelet count 239,000/microliter, and WBC count 7720/microliter. His peripheral blood smear shows normal WBC morphology and RBCs with mild poikilocytosis and a few target cells. His serum vitamin B12 is 512 pg/mL and folate 4.7 ng/mL. His serum haptoglobin is 151 mg/dL. Direct and indirect Coombs tests are negative. Which of the following underlying conditions is most likely to explain his findings? A Chronic lymphocytic leukemia B Peptic ulcer disease C Lead poisoning D Chronic alcohol abuse E Hereditary spherocytosis

D Chronic alcohol abuse (D) CORRECT. There is mild macrocytosis with normal B12 and folate, without evidence for significant hemolysis. Liver disease can lead to RBC membrane abnormalities, with the presence of a few target cells on the peripheral blood smear as well as macrocytes. Alcohol can also directly affect RBC maturation. Chronic alcohol abusers may also have poor diets lacking in folate. An MCV >105 fL is much more likely to result from megaloblastic anemia (B12 or folate deficiency).

A 5-year-old female is kept indoors during the day on the advice of the family physician, who has determined that there is a family history of skin cancers. Which of the following mechanisms explains why the child is at risk with sun exposure: A Balanced chromosomal translocation B Rb-1 mutation C c-erb B2 amplification D Defective DNA repair E k-ras activation

D Defective DNA repair

A 45-year-old man has had a fever and a productive cough for the past 3 days. On physical examination there is dullness to percussion over the right upper lung. His temperature is 37.9°C. A chest radiograph reveals right upper lobe consolidation. Laboratory findings include serum total protein of 6.0 g/dL, albumin 2.7 g/dL, AST 185 U/L, ALT 98 U/L, total bilirubin 1.0 mg/dL, alkaline phosphatase 31 U/L, and prothrombin time 20 sec. An abdominal CT scan shows hepatomegaly with decreased hepatic attenuation. Which of the following conditions is the most likely underlying cause of death? A Alpha-1-antitrypsin deficiency B Wilson disease C Acute hepatitis C D Diabetes mellitus E Biliary tract lithiasis

D Diabetes mellitus (D) CORRECT. Big fatty livers with decreased attenuation on CT scans are often seen in conjunction with chronic alcoholism. In the absence of a history of chronic alcohol abuse, non-alcoholic fatty liver (NAFL) is the likely cause, and NAFL can be associated with obesity and diabetes mellitus. Microscopically, the pattern will be macrovesicular steatosis, with large lipid vacuoles filling hepatocytes.

An 83-year-old woman fell and broke her left wrist. She underwent open reduction with internal fixation of the radial head fracture. Postoperatively she received heparin prophylaxis for thromboembolism and diuretics to treat pulmonary edema. Laboratory studies showed: On admission: Hgb 13.2 g/dL, Hct 39.1%, MCV 85 fL, platelet count 209,000/microliter, WBC count 5720/microliter, prothrombin time 13 seconds, partial thromboplastin time 28 seconds 1 week later: Hgb 13 g/dL, Hct 38.8%, MCV 86 fL, platelet count 101,000/microliter, WBC count 6310/microliter, prothrombin time 12 seconds, partial thromboplastin time 27 seconds She suddenly developed difficulty in moving her right arm. What is the most likely cause for her findings? A Hypersplenism B Idiopathic thrombocytopenic purpura C Disseminated intravascular coagulation D Drug-induced thrombocytopenia E Thrombotic-thrombocytopenic purpura

D Drug-induced thrombocytopenia (D) CORRECT. She has heparin-induced thrombocytopenia. In about 5% of patients receiving heparin, antibodies develop to a complex of platelet factor 4 with heparin, and in 5 to 14 days there is a marked drop in platelet count. The feared complication is thrombosis ('white clot' syndrome), which can be arterial or venous, and in this patient a thrombotic stroke is likely to have occurred. Low molecular weight heparins are less likely to have this complication.

A 55 year old diving instructor from Cancun, Mexico, has a number of 0.5 to 1 cm rounded, flat, tan-brown to slightly erythematous lesions with a rough, sandpaper-like consistency on the face, arms, and dorsa of both hands. Which of the following statements regarding this condition is LEAST likely to be correct: A The lesions are probably related to his job B He has a risk for development of squamous cell carcinoma C One of the features on biopsy will be upper dermal elastosis D The lesions are infectious to others E It took years for these lesions to develop

D The lesions are infectious to others

After a summertime camping trip in the Green mountains of Vermont, a 29-year-old man has developed a mild watery diarrhea for the past week. While on the trip he drank water from the mountain streams. A physical examination reveals no abdominal pain or masses. He is afebrile. Bowel sounds are present. His stool is negative for occult blood. The diarrhea abates in 3 weeks. His two children are similarly affected. Which of the following infectious agents most likely caused his disease? A Rotavirus B Shigella flexneri C Vibrio cholerae D Giardia duodenalis E Entamoeba histolytica F Cryptosporidium parvum G Salmonella enterica H Norovirus

D Giardia duodenalis (D) CORRECT. Giardiasis is typically a non-life threatening nuisance in immunocompetent persons. The organisms are found in contaminated water, particularly in areas such as apparently pristine, remote, mountains not considered to be a risk for infectious diseases. He had not read his Sierra Club guide in regard to treatment of drinking water while camping.

A 32-year-old man has had worsening headaches for the past 2 months. On physical examination he is afebrile. He has no lymphadenopathy or hepatosplenomegaly. Laboratory studies shows Hgb 12 g/dL, platelet count 250,000/microliter, and WBC count 6000/microliter with differential count of 80% granulocytes, 10% lymphocytes, and 10% monocytes. A head CT scan reveals a 3 cm mass lesion to the right of midline next to the lateral ventricle. A stereotaxic brain biopsy is performed and microscopic examination shows diffuse large B cell lymphoma. Which of the following laboratory test findings is this patient most likely to have? A Elevated terminal deoxyribonucleodidyl transferase B Bence-Jones proteinuria C Elevated serum IgM D HIV-1 RNA of 80,000 copies/mL E Lymphoma positive for tartrate-resistant acid phosphatase

D HIV-1 RNA of 80,000 copies/mL (D) CORRECT. He has a cerebral lymphoma typical for AIDS with HIV infection. His lymphopenia is due to a reduced CD4 T-cell count.

A study is conducted to determine what changes in the size of the spleen take place with hematologic disorders. The spleen sizes are estimated from CT scans for adult patients who developed complications of their hematologic disease. For which of the following diseases is the spleen most likely to remain normal in size? A Autoimmune hemolytic anemia B Chronic alcohol abuse C Myeloproliferative disorder D Idiopathic thrombocytopenic purpura E Sickle cell anemia

D Idiopathic thrombocytopenic purpura (D) CORRECT. Though with ITP there are circulating antibodies to platelets that lead to platelet destruction, the spleen itself is usually not enlarged.

Which of the following statements about a slowly enlarging 0.7 cm firm mass with a pearly appearance and central umbilication involving the lower eyelid of a 72 year old male is INCORRECT: A The lesion is slow growing B Metastasis is highly unlikely C He may also have actinic keratoses D If left alone, it is unlikely to affect his vision E The lesion may be pigmented

D If left alone, it is unlikely to affect his vision

A tan, flat, 1 cm rough-surfaced, non-tender papule on the dorsal surface of the hand of a 19-year-old male is most likely to be: A Herpetic dermatitis B A syphilitic chancre C Tinea versicolor D Verruca vulgaris E A seborrheic keratosis

D Verruca vulgaris

A 2-year-old boy has had a seborrheic eruption over the scalp and trunk over the past month. He then develops a right ear ache. On physical examination the right tympanic membrane is erythematous and bulging. He has hepatosplenomegaly and generalized lymphadenopathy. Laboratory studies show Hgb 9.5 g/dL, Hct 28.7%, MCV 90 fL, platelet count 58,000/microliter, and WBC count 3540/microliter. A bone marrow biopsy is performed and on microscopic examination shows 100% cellularity with extensive infiltration by cells resembling macrophages that express CD1a antigen and, by electron microscopy, have prominent HX bodies (Birbeck granules). Which of the following conditions is most likely to produce this boy's findings? A Myeloproliferative disorder B Plasmodium vivax infection C Hodgkin lymphoma, lymphocyte depletion type D Langerhans cell histiocytosis E AIDS

D Langerhans cell histiocytosis (D) CORRECT. The Langerhans cell histiocytoses include Letterer-Siwe disease (as in this case, it is typically a disseminated disease of children), and localized eosinophilic granuloma (often involving bone).

A 12-year-old girl has the sudden onset of severe abdominal pain and back pain. On physical examination her abdomen is diffusely tender, but there are no masses. She is afebrile. A CBC shows Hgb 6.5 g/dL, Hct 19.0%, MCV 99 fL, platelet count 149,000/microliter, and WBC count 11,200/microliter. Examination of her peripheral blood smear shows nucleated RBCs and sickled RBCs. Which of the following types of gene mutation is she most likely to have? A Deletion B Duplication C Insertion D Missense E Nonsense F Splice site G Tandem repeat

D Missense (D) CORRECT. Missense mutations involve a change in a single base pair for a amino acid. The defect in sickle cell anemia is a single amino acid substitution (valine for glutamic acid), but the beta globin chain is still made. The gene mutation originated in places such as West Africa where selection pressure from falciparum malaria gave heterozygotes a selective advantage. The gene frequency may less commonly be present in some Mediterranean and eastern Arabian populations. There is enough fetal hemoglobin at birth and through infancy to prevent significant sickling with sickle cell disease.

A 62-year-old man has had dull, constant back pain for 3 months. He recently developed a cough productive of yellowish sputum. On physical examination there are crackles at the right lung base. A plain film radiograph of the spine reveals several 1 to 2 cm lytic lesions of the vertebral bodies. Laboratory studies show glucose 78 mg/dL, urea nitrogen 49 mg/dL, creatinine 5 mg/dL, total protein 8.3 g/dL, albumin 3.7 g/dL, alkaline phosphatase 176 U/L, AST 45 U/L, ALT 22 U/L, and total bilirubin 1.2 mg/dL. A sputum culture grows Streptococcus pneumoniae. Which of the following pathologic findings is most likely to be seen in a bone marrow biopsy from this man? A Scattered small granulomas B Nodules of small mature lymphocytes C Occasional Reed-Sternberg cells D Numerous plasma cells E Hypercellularity with many blasts

D Numerous plasma cells (D) CORRECT. The findings suggest multiple myeloma. He has a markedly increased level of serum globulins. The renal failure from light chains deposited in the kidneys, and the increased risk for encapsulated bacterial infections is typical. The lytic bone lesions are collections of plasma cells.

A 62-year-old man has had anorexia, vomiting, and vague abdominal pain accompanied by weight loss of 6 kg over the past 2 months. Physical examination reveals supraclavicular non-tender lymphadenopathy. He becomes progressively cachectic. An abdominal CT scan shows the stomach is shrunken with the gastric wall thickened to 1 cm and with extensive overlying mucosal erosions. Multiple masses from 1 to 4 cm in size are scattered within the liver. Which of the following conditions most likely preceded development of his illness? A Acquired immunodeficiency syndrome B Hyperglycemia C Chronic alcoholism D Pernicious anemia E Systemic sclerosis F Use of NSAIDS

D Pernicious anemia (D) CORRECT. This is linitis plastica of the stomach, which typically has a signet ring cell pattern of adenocarcinoma diffusely infiltrating the stomach. Autoimmune gastritis is a risk factor for this condition. The atrophic gastritis leads to loss of parietal cells that produce intrinsic factor needed for B12 absorption.

Following a traumatic laceration to the right upper chest, a 36 year old African-American male notes over the next few months the development of disfiguring nodular scarring in the region of the healed laceration. Scar revision with excision of the lesion is most likely to show: A Necrotizing acute inflammation B Granulomas with caseous necrosis C Apoptosis D Dense collagen bundles E Atypical squamous epithelium

D. Dense collagen bundles

The scabies mite (Sarcoptes scabiei): A Produces a pre-neoplastic lesion B Affects mainly immunocompromised adults C Is usually acquired as a sexually transmitted disease D Lives in burrows under the stratum corneum on the hands E Does not affect sun-exposed areas of the body

D. Lives in burrows under the stratum corneum on the hands

A 46-year-old plumber has a 2 cm circumscribed necrotic ulcer on his right arm that has not healed in 3 months. You should suspect: A Scabies B Herpes simplex C Candida albicans D Basal cell carcinoma E Brown recluse spider bite

E Brown recluse spider bite

For the past 4 months, a 62-year-old previously healthy man has noted increasing fatigue and shortness of breath with minimal exercise. He has felt some abdominal discomfort over the past month. On physical examination he has non-tender cervical lymphadenopathy. The liver span is 15 cm in the right mid-clavicular line; the edge is smooth and palpable just below right costal margin. The spleen is palpated 3 cm below left costal margin on inspiration. A CBC shows WBC count 23,100/microliter with 16 segs, 2 bands, 78 lymphs, and 4 monos, Hgb 11.9 g/dL, Hct 36%, MCV 90, and platelet count 277,300/microliter. The direct Coombs test is positive. Which of the following is the most likely diagnosis? A Leukemoid reaction B Chronic myelogenous leukemia C Acute myelogenous leukemia D Acute lymphocytic leukemia E Chronic lymphocytic leukemia F Systemic lupus erythematosus

E Chronic lymphocytic leukemia (E) CORRECT. Most of the circulating cells are small, mature lymphocytes with CLL. Most persons with CLL are older adults. CLL can have a tissue component called small lymphocytic lymphoma (SLL) with the same small lymphocytes infiltrating organs such as liver and spleen.

A 22-year-old woman has had progressive malaise for the past year. She has become increasingly obtunded over the past week. On physical examination she is afebrile. Laboratory studies show a plasma ammonia of 55 micromol/L along with serum total bilirubin of 5.8 mg/dL, direct bilirubin 4.6 mg/dL, AST 110 U/L, and ALT 135 U/L. Her serum ceruloplasmin is 14 mg/dL. The antimitochondrial antibody test is negative. A liver biopsy is performed and microscopic examination reveals increased copper deposition. Which of the following ocular findings is most likely to be present in this woman? A Bilateral papilledema B Macular degeneration C Proliferative retinopathy D Crystalline lens cataract formation E Corneal Kayser-Fleischer rings F Canal of Schlemm occlusion

E Corneal Kayser-Fleischer rings (E) CORRECT. These pale tan rings can be seen with a slit lamp examination. They are characteristic for Wilson disease, an autosomal recessive disorder with mutation in the ATP7B gene that encodes for a copper-transporting ATPase. Patients have decreased serum ceruloplasmin, the copper-carrying protein, and increased tissue deposition of copper, particularly in liver, eye, and basal ganglia of brain. Untreated cases such as this one can lead to end stage liver disease. Ammonia increases most with acute liver failure.

A 44 year old woman is concerned about the change in color with recent increase in size of a pigmented lesion on her left shoulder. The brownish-black nodular lesion has irregular borders. It is completely excised. Microscopically, the lesion is composed of large, pleomorphic cells with enlarged nuclei that have prominent large nucleoli. The scant cytoplasm of these cells contains a fine black pigment. Which of the following parameters is most important in determination of the prognosis for this patient: A Age of the patient B Diameter of the lesion C History of sun exposure D Location on the skin E Depth of the lesion

E Depth of the lesion

A 10-year-old girl has exhibited increasing sluggishness with poorer performance in school over the past year. She has not had increased numbers of infections. The child now complains of headaches. A physical examination shows no hepatosplenomegaly or lymphadenopathy. A CBC shows: Hgb 11.8 g/dL, Hct 33.9%, MCV 71 fL, platelet count 293,000/microliter, and WBC count 8160/microliter. Examination of her peripheral blood smear shows basophilic stippling of erythrocytes. The serum haptoglobin is 5 mg/dL. Which of the following laboratory test findings is most likely to be present in this girl A Hemoglobin S on electrophoresis B Increased osmotic fragility C Positive direct Coombs test D Decreased serum iron E Elevated free erythrocyte protoporphyrin

E Elevated free erythrocyte protoporphyrin (E) CORRECT. She has lead poisoning. Lead inhibits incorporation of iron into heme, leading to elevated zinc protoporphyrin and free erythrocyte protoporphyrin. The diminished heme synthesis leads to a hypochromic, microcytic anemia, and there may be mild hemolysis. Basophilic stippling can be an indicator of toxic injury to RBCs.

A 25-year-old African-American man is given anti-malarial prophylaxis for a trip to West Africa. Over the next week he develops increasing fatigue. On physical examination there are no abnormal findings. Laboratory studies show a hematocrit of 30%. Examination of his peripheral blood smear shows red blood cells with numerous Heinz bodies. There is a family history of this disorder, with males, but not females, affected. Which of the following is the most likely diagnosis? A Beta-thalassemia B Sickle cell anemia C Alpha-thalassemia D Hereditary spherocytosis E G6PD deficiency

E G6PD deficiency (E) CORRECT. He has glucose-6-phosphate dehydrogenase (G6PD) deficiency, which can result in a hemolytic anemia on exposure to oxidizing agents including certain drugs such as antimalarials. This is an X-linked disorder. The Heinz bodies within the RBCs are formed from denatured hemoglobin.

A 78-year-old woman has developed increasing dyspnea for the past 2 weeks. On physical examination she has diffuse rales in all lung fields. Scleral icterus is noted. A CBC shows Hgb 7.1, Hct 22.2, MCV 93 fL, platelet count 205,000/microliter, and WBC count 6500/microliter with differential count of 60 segs, 4 bands, 25 lymphs, 9 monos, and 2 eos with 10 nucleated RBCs/100 WBCs. Which of the following is the most likely diagnosis? A Iron deficiency anemia B Pernicious anemia C Anemia of chronic disease D Sickle cell anemia E Hemolytic anemia

E Hemolytic anemia (E) CORRECT. She may have an autoimmune hemolytic anemia, and may have an underlying malignancy such as lymphoma. The icterus is consistent with hyperbilirubinemia from hemolysis. Nucleated RBCs are consistent with high marrow output of erythroid cells. The marked anemia has led to high output congestive heart failure with pulmonary edema.

A 40-year-old man has a long history of chronic alcohol abuse. On physical examination his liver edge is firm on palpation of the abdomen, but liver span does not appear to be increased. An abdominal CT scan reveals a cirrhotic liver. He joins a support group for persons with chronic alcohol abuse and he stops drinking. Despite his continued abstinence from alcohol, he most likely remains at risk for development of which of the following diseases? A Hepatic adenoma B Focal nodular hyperplasia C Cholelithiasis D Angiosarcoma E Hepatocellular carcinoma F Non-Hodgkin lymphoma G Hemangioma

E Hepatocellular carcinoma (E) CORRECT. Hepatocellular carcinoma occurs most often in the setting of cirrhosis (which occurs most often from chronic alcoholism and from chronic viral hepatitis B and C). The liver remodels itself over years, so the cirrhosis is slowly reversible, with decreasing carcinoma risk.

A 53-year-old man has had constant dull pain in his lower right back for the past 4 months. On physical examination there is tenderness on percussion of his right costovertebral angle. An abdominal CT scan reveals a 6 cm mass in the upper pole of the right kidney. A CBC shows: Hgb 21.3 g/dL, Hct 64.0%, MCV 96 fL, platelet count 199,000/microliter, and WBC count 8230/microliter. Serum chemistries include glucose 77 mg/dL, urea nitrogen 17 mg/dL, and creatinine 1.1 mg/dL. Which of the following is the most likely cause for his findings? A Polycythemia rubra vera B Erythroleukemia C Hemophilia A D Diabetes insipidus E Increased erythropoietin

E Increased erythropoietin (E) CORRECT. He has a secondary form of polycythemia. Renal cell carcinomas are known to secrete erythropoietin and lead to this paraneoplastic effect with polycythemia.

A clinical study is performed with subjects who are adults found to have anemia. Their clinical histories and laboratory findings are reviewed. It is observed that ingestion of a drug preceded development of the anemia in some of the subjects, but not in others. Which of the following conditions is most likely to be found in persons without a history of drug ingestion? A G6PD deficiency B Autoimmune hemolytic anemia C Macrocytic anemia D Aplastic anemia E Microcytic anemia

E Microcytic anemia (E) CORRECT. Microcytic anemia is usually the result of an iron deficient state not associated with drug usage.

A 55-year-old man has had fatigue, fever, and episodes of epistaxis for the past 3 months. On physical examination his temperature is 37.4°C. Laboratory studies show Hgb 12.5 g/dL, Hct 37.6%, MCV 89 fL, platelet count 170,000/microliter, and WBC count 52,000/microliter. Examination of his peripheral blood smear shows large blasts with Auer rods. Which of the following risk factors most likely preceded development of his current illness? A Malaria B Infectious mononucleosis C Diabetes mellitus D Beta-thalassemia E Myelodysplasia

E Myelodysplasia (E) CORRECT. Auer rods are formed of the cytoplasmic granules of the myeloid blasts of acute myelogenous leukemia (AML) and are a typical finding with AML. Myelodysplastic syndromes can precede development of AML, as can some cases of myeloproliferative disorders, paroxysmal nocturnal hemoglobinuria, and chemotherapeutic regimens.

A 38 year lifeguard has been working at San Onofre State Beach for the past 16 years each summer. He is at risk for each of the following lesions EXCEPT: A Actinic keratosis B Squamous cell carcinoma C Melanoma D Basal cell carcinoma E Neurofibroma

E Neurofibroma

A 25-year-old man has noted cramping abdominal pain for the past week associated with fever and low-volume diarrhea. On physical examination, there is right lower quadrant tenderness. Bowel sounds are present. His stool is positive for occult blood. A colonoscopy reveals mucosal edema and ulceration in the ascending colon, but the transverse and descending portions of the colon are not affected. Laboratory studies show serum anti-Saccharomyces cerevisiae antibodies. Which of the following microscopic findings is most likely to be present in biopsies from his colon? A Crypt abscesses B Entameba histolytica organisms C Adenocarcinoma D Band-like mucosal fibrosis E Non-caseating granulomas F Necrotizing vasculitis

E Non-caseating granulomas (E) CORRECT. This history is most typical for Crohn disease, which is a form of inflammatory bowel disease that tends to involve the bowel in a segmental pattern.

A 55-year-old diabetic male has necrotizing fasciitis involving the left upper thigh. Necrotizing fasciitis is characterized by which of the following statements: A This process tends to remain localized. B Histologically, foreign body giant cells are numerous. C It is usually due to viral infection. D It is typically the result of severe atherosclerosis. E Penetrating trauma may precede its occurrence.

E Penetrating trauma may precede its occurrence.

A 20-year-old healthy man incurs blunt force trauma to the abdomen in a motor vehicle accident. On physical examination he has upper abdominal tenderness. An abdominal CT scan reveals a splenic hematoma. At laparotomy a splenectomy is performed. Following splenectomy, which of the following peripheral blood morphologic findings is most likely to be present? A Tear drop cells B Elliptocytes C Target cells D Macro-ovalocytes E RBC inclusions

E RBC inclusions (E) CORRECT. Howell-Jolly bodies and Pappenheimer bodies are seen within RBC's in splenectomized patients. A functioning spleen would normally remove such inclusions.

A 3-year-old child is noted to have small pinpoint hemorrhages on the skin, appearing over the past 3 days. On examination the child's vital signs are normal. There are petechae over skin of extremities and trunk. A CBC shows Hgb 14.3 g/dL, Hct 43%, MCV 90 fL, platelet count 19,300/microliter, and WBC count 9370/microliter. This condition resolves over the next month without treatment. Which of the following is the most likely antecedent event for this child's illness? A Acetylsalicylic acid (aspirin) ingestion B Congenital HIV infection C Dietary cobalamin deficiency D Repetitive trauma E Respiratory syncytial virus infection F Sulfonamide ingestion

E Respiratory syncytial virus infection (E) CORRECT. This is acute immune thrombocytopenia in a child. It is usually self-limited. In most cases the predisposing event is a viral infection that sets off an immune response directed specifically at platelet production.

Excisional biopsy of a solitary 1 cm diameter pigmented lesion from the upper back on your 38 year old female patient shows a malignant melanoma that is 2 mm in thickness, with margins clear. These findings most strongly suggests that: A She will not have to worry further about this lesion B The lesion has occurred in a non sun-exposed area C There is a genetic basis for the occurrence of this lesion D Human papillomavirus infection was present E There may be metastases within 5 years

E There may be metastases within 5 years

A 46-year-old man has had worsening arthritis and swelling of his feet for the past year. On physical examination he has rales audible in all lung fields. A chest radiograph shows cardiomegaly and pulmonary edema. Laboratory studies show Hgb 13.0 g/dL, Hct 39.1%, MCV 86 fL, platelet count 255,500/uL, and WBC count 5920/uL. His serum iron is 406 microgram/mL with iron binding capacity 440 microgram/mL and ferritin 830 ng/mL. Which of the following is the most likely diagnosis? A Beta-thalassemia B Autoimmune hemolytic anemia C Anemia of chronic disease D Polycythemia vera E Pernicious anemia F Hereditary hemochromatosis

F Hereditary hemochromatosis (F) CORRECT. Hereditary hemochromatosis results from increased iron absorption with markedly increased iron stores. The iron accumulation in tissues results in manifestations such as hepatomegaly, skin pigmentation, diabetes mellitus, heart disease, arthritis, and hypogonadism.

A 23-year-old primigravida gives birth at term following an uncomplicated pregnancy to a male infant with no apparent congenital anomalies. At 4 weeks of age the infant begins to exhibit forceful vomiting after each feeding. The infant had been fine previously and gaining weight normally. Which of the following conditions is the probable cause for his vomiting? A Congenital duodenal atresia B Necrotizing enterocolitis C Mallory-Weiss syndrome D Hirschsprung disease E Tracheo-esophageal fistula F Pyloric stenosis

F Pyloric stenosis (F) CORRECT. The male sex, age, and symptoms are all quite typical for pyloric stenosis, a condition that exhibits the genetic feature called the 'threshold of liability' in which males are more likely to have the disease (lower threshold) if born into a family with girls affected (higher threshold, and thus, more genetic tendencies for the disease to pass on).