USMLE-Rx
A 40 yo white man presents to the ED complaining of burning retrosternal chest pain after meals. The pain is relieved by antacids. The patient's ECG is normal, and x-ray of the chest is remarkable for an 8cm hiatal hernia. This patient is at risk of developing which of the following types of cancer? A. Adenocarcinoma of the esophagus B. Gastric adenocarcinoma C. Krukenberg tumor D. Non-small cell adenocarcinoma of the lung E. Squamous cell carcinoma of the esophagus
A. Adenocarcinoma of the esophagus The quality and location of this patient's pain, combined with its alleviation with medication and the radiographic finds, are suggestive of GERD. GERD increases the risk of developing esophageal mucosal metaplasia called Barrett esophagus. In turn, patients with Barrett esophagus are at increased risk for developing adenocarcinoma of the distal esophagus. Barrett esophagus is diagnosed by endoscopy, and must be followed with annual endoscopy and biopsy to monitor for adenocarcinoma. Hiatal hernia, though commonly asymptomatic, often presents with symptoms of GERD due to anatomic disruption of the LES, impairing its ability to stop reflux of stomach contents. Because of this chronic reflux, symptomatic hiatal hernias are risk factors for Barrett esophagus and esophageal adenocarcinoma if left untreated.
After spending 5 days in the hospital being treated for exacerbation of CHF, a 76 yo man develops a fever. Urine cultures reveal Enterococcus. An antibiotic is administered and the patient's fever subsides. However, 3 days later, the patient develops watery stools and complains of abdominal pain. Which of the following antibiotics was most likely initially administered to this patient to treat the Enterococcus infection? A. Ampicillin B. Ciprofloxacin C. Clindamycin D. Metronidazole E. TMP-SMX
A. Ampicillin This patient has diarrhea caused by C. dif. C. dif releases a toxin that causes watery diarrhea. Additionally, it produces an exotoxin that is cytotoxic to the colonic mucosa, which leads to pseudomembrane formation in later stages of disease. Classically, the use of ampicillin or clindamycin lead to C.dif overgrowth and pseudomembranous colitis. The patient in this case had an Enterococcus infection, for which ampicillin is considered 1st line.
A 50 yo man with a history of alcoholism present to the clinic complaint of abdominal pain that radiates to his back. He describes non blood emesis for the past 2 days and being unable to eat or drink anything without vomiting. The physician suspects acute alcoholic pancreatitis and starts fluid resuscitation and pain control. A day later, the patient's condition is improved and he is told that alcohol consumption is doing permanent damage to his pancreas. When the patient asks the purpose of the pancreas, the physician responds that it is responsible for a variety of endocrine and exocrine functions. Which of the following is a product of pancreatic exocrine cells? A. Amylase B. Cholecystokinin C. Glucagon D. Insulin E. Somatostatin
A. Amylase Located posterior to the stomach, the pancreas has both endocrine and exocrine functions. These are among is endocrine functions: a-islet cells secrete glucagon, b-islet cells secrete insulin, and g-islet cells secrete somatostatin. These hormones are secreted directly into the bloodstream. The pancreas also has exocrine functions, such as the excretion of digestive enzymes. These include amylase, which functions in the digestion of carbohydrates; lipase, which helps in fat digestion; and trypsin and chymotrypsin, which aid in protein digestion. Acing cells are responsible for the excretion of these products into pancreatic ducts, which then empty into the common bile duct, to end up in the duodenum. Acinar cells are large and have more eosinophilic cytoplasm than pancreatic endocrine cells. Look for these pyramidal-shaped cells near pancreatic ducts and centroacinar cells. Acinar cells are polarized into apical and basal regions. The apical regions stain acidophilic because of their membrane-bound secretory vesicles and the basal regions stain basophilic because of their content of RER.
A 44 yo woman who is a smoker with a long-standing history of RA presents to the physician because of epigastric pain, vomiting, and weight gain. The abdominal pain sometimes wakes her at night and she feels pain if she has not eaten in several hours. During workup of the patient's complaints, a biopsy was taken from the tissue involved in the disease pathology. In which of the following locations would one expect to see hypertrophy? A. Brunner glands B. Ileum C. Mucosa of the antrum of the stomach D. Peyer patches E. Tubular glands int eh funds of the stomach
A. Brunner glands this patient likely has an ulcer, which occurs most frequently in the first part of the duodenum, the stomach, or lower end of the esophagus. With a history of RA, the patient most likely has been using NSAIDs chronically; these drugs inhibit prostaglandins that normally function to protect the mucosal lining. Smoking and H.pylori infection also increase the risk of peptic ulcer disease. The patient is complaining of weight gain, which likely is related to the fact that the pain of duodenal ulcers decreases after a meal (this is in contrast to gastric ulcers, in which pain usually increases with meals, resulting in weight loss). Hypertrophy of Brunner glands may be seen on biopsy. Brunner glands are found only in the submucosa of the duodenum. The presence of chyme in the duodenum stimulates Brunner glands to secrete alkaline mucus that helps neutralize the acidic contents that arrive from eh stomach, thus protecting the duodenal mucosa. As duodenal ulcers are always associated with hyper secretion of gastric acid (unlike gastric ulcers, which may or may not be), one would also expect to see hypertrophy of Brunner glands in a patient with a duodenal ulcer.
24 hours after birth, a male neonate has not passed meconium. A chloride sweat test is ordered and found to be positive. The infant's parents are counseled on his need for long term follow-up and treatment. Which of the following is the embryonic origin of another structure that is often affected in this infant's condition? A. Mesonephric duct B. Urogenital folds C. Vitelline duct D. Thyroglossal duct E. Allantoic duct
A. Mesonephric duct This boy has CF as demonstrated by his failure to pass meconium (meconium ileus) and a positive chloride sweat test. At least 95% of males with cystic fibrosis are infertile as a result of the improper development of the mesonephric (Wolffian) duct system, which most often leads to a defective vas deferens. The vas deferent, along with the epididymis, seminal vesicles and ejaculatory duct, is derived from the mesonephric duct. Additional abnormalities in cystic fibrosis include exocrine pancreas deficiency, late onset puberty, chronic sinusitis, and chronic URT infections.
What vitamin is stored exclusively by cells located in the space of Disse adjacent to hepatocytes? A. Vitamin A B. Vitamin C C. Vitamin D D. Vitamin E E. Vitamin K
A. Vitamin A Hepatic stellate cells, also called Ito cells or lipocytes, are found in the liver. They are located in the space of Disse adjacent to hepatocytes. These cells are difficult to see on light microscopy because they have lipid droplets containing vitamin A in their cytoplasm. Additionally, they produce collagen. When the liver is injured, collagen production is increased, which leads to the fibrosis seen in hepatic cirrhosis. Vitamin A, in the form of isotretinoin, is used in dermatology to treat acne.
A 78 yo man is brought to the hospital because of fever and acute onset of LLQ pain. About a week ago, he was seen by his PCP for painless rectal bleeding. What is the best diagnostic test after the patient is appropriately treated and the acute episode has resolved? A. Abdominal ultrasound B. Colonoscopy C. CT of the abdomen D. MRI of the abdomen E. Upright abdominal x-ray
B. Colonoscopy Painless rectal bleeding in an elderly individual (especially with a history of constipation or poor fiber intake) suggests diverticulosis (false diverticula that involve only mucosa and submucosa), most commonly affecting the sigmoid colon. This patient's lower left quadrant abdominal pain indicates that he is now suffering from acute diverticulitis, which is inflammation of one or more diverticula. The lab values show marked leukocytosis, suggesting active infection and iron-deficient microcytic anemia (low hemoglobin and low mean corpuscular volume). This could result from his past bleeding episodes, however, it could also be a sign of chronic occult bleeding from an undiagnosed carcinoma. Diverticulitis is treated with ciprofloxacin and metronidazole. After the episode has resolved, the patient should undergo colonoscopy to rule out malignancy. Colonoscopy is contraindicated during an acute episode of diverticulitis due to increased risk of bowel perforation, so physicians will commonly wait 6 weeks after resolution of symptoms to ensure that the inflammation has subsided and that this risk of perforation has decreased.
A 53 yo patient present to the clinic because of lethargy, malaise, and peripheral edema. His pulse is 96/min and body habits shows wide girth. His chart reveals that he was recently involved in several motor vehicle collisions. Lab studies show: WBC count: 12,000 Hemoglobin: 11 g/dL Hematocrit: 35% Aspartate aminotransferase: 150 U/L Alanine aminotransferase: 50 U/L Alkaline phosphatase: 80 U/L What is the major physiologic mechanism for this patient's edema? A. Constriction of arterioles B. Decreased production of serum proteins C. Increased permeability of capillaries D. Increased permeability of glomeruli E. Lymphatic blockage
B. Decreased production of serum proteins The patient has a presentation that is consistent with alcoholic hepatitis. This is evidenced by a ratio of aspartate aminotransferase to alanine aminotransferase (AST:ALT ratio) >1.50 and a normal alkaline phosphatase level (elevation would be more suggestive of biliary obstruction). He also shows classic signs of metabolic encephalopathy, ascites and edema. The mild anemia is the result of the suppressive effects of alcohol on the bone marrow. The major mechanism contributing to edema in this disease is the decreased production of serum proteins (eg, albumin) by the damaged liver. Therefore, the plasma oncotic pressure is decreased, allowing fluid to flow out of the capillaries.
The small intestine is responsible for the absorption of nutrients and electrolytes. The mucosa and submucosa are folded into villi, fingerlike projections containing connective tissue, capillaries and lacteals, to maximize absorptive capacity. Which of the following macromolecules can cross the epithelial cell apical membrane by simple diffusion? A. Amino acids B. Free fatty acids C. Monosaccharides D. Triglycerides
B. Free fatty acids Free fatty acids are nonpolar hydrophobic molecules and are thus able to cross the cell membrane by simple diffusion. The phospholipid bilayer of cell membranes prevents polar solutes (amino acids, nucleic acids, carbs, proteins and ions) from diffusing across the membrane but allow the simple diffusion of hydrophobic molecules. Pancreatic lipase and bile salts metabolize triglycerides into free fatty acids and monoglycerides. They cross the villous epithelial cell membrane of the SI via simple diffusion and specific transporters. Once inside the enterocyte, fatty acids and monoglyceride are re-esterifeid to triglycerides in the sER. Processing continues in the Golgi forming chylomicrons containing cholesterol, lipoproteins, and other lipids. Chylomicrons are transported into the lacteals and lymphatic vessels and finally delivered into the systemic blood for use by the body.
A 28 yo woman has a 1 year history of recurrent abdominal pain relieved by defecation. She reports that her diarrhea has gotten worse in the past 2 weeks, since she started a new job. Her examination is unremarkable except for mild abdominal tenderness. She denies any recent travel, change in eating habits, or sick contacts. She has attempted to avoid gluten and dairy products in the past but with no effect on her symptoms. Her lab studies show the following results: Hemoglobin: 13 g/dL Hematocrit: 39% WBC: 6000/mm3 Platelet count: 200,000/mm3 ESR: 8mm/h Which of the following pharmacologic therapies would be most appropriate in the treatment of this patient's symptoms? A. Bismuth subsalicylate B. Loperamide C. Metronidazole D. Octrotide E. Omeprazole F. Trimethoprim-sulfamethoxazole
B. Loperamide This young woman has IBS. IBS, a diagnosis of exclusion, is an idiopathic functional disorder characterized by abdominal pain and changes in bowl habits that increase with stress and are relieved with bowel movements. A normal CBC and ESR are consistent with IBS. Treatment is symptomatic. In a patient suffering from diarrhea, use loperamide
A 42 yo black man with a history of B-thalassemia presents to the clinic with concerns for increasing fatigue and abnormal skin pigmentation. After a number of abnormal lab tests, an echocardiogram demonstrates severe dilated cardiomyopathy. What is the most plausible mechanism for this patient's presenting symptoms? A. Anemia of chronic disease B. Multiple blood transfusions C. Mutation in HFE gene D. Porphyria cutanea tarda E. Sideroblastic anemia
B. Multiple blood transfusions This patient would be receiving multiple blood transfusions for treatment of his beta thalassemia which can result in secondary hemochromatosis. Primary hemochromatosis usually demonstrates autosomal recessive inheritance. Secondary hemochromatosis is most often a result of multiple blood transfusions. Clinically, both will present with bronze skin, liver disease, diabetes, cardiac dysfunction (arrhythmias or cardiomyopathy) and secondary hypogonadism.
A 32 yo woman complains of alternating bouts of diarrhea and constipation and reports chronic abdominal pain relieved by frequent bowel movements. her symptoms are exacerbated by stress The patient denies fever or weight loss. She has a negative Hemoccult fecal occult blood test. Colonoscopy and endoscopy reveal no abnormalities. The most likely diagnosis in this patient is commonly associated with which of the following findings? A. Leukocytosis B. Normal biopsy C. Primary sclerosing cholangitis D. Strictures in the small bowel E. Villous flattening in the small intestine
B. Normal biopsy Any biopsy would like show normal structures. Irritable bowel syndrome is a function GI disorder characterized by abdominal pain and altered bowel habits in the absence of demonstrable organic pathology It is a diagnosis of exclusion based on clinical features such as the ones presented. Most commonly, patients have alternating diarrhea and constipation, chronic abdominal pain that improves with pooping, a change in stool frequency and consistency, and onset after emotional and/or stressful life events. These symptoms occur in the absence of fevers, low GI bleeding, leukocytosis and weight loss.
A newborn develops marked jaundice and kernicterus within weeks of birth. Blood tests reveal ALT=16 U/L, AST=14 U/L, and total bilirubin=36 mg/dL. Urine tests are negative for bilirubin. Treatment attempt with phenobarbital is unsuccessful. The infant's condition deteriorates over the next 2 months and he dies. What is the underlying cause of the infant's death? A. Elevated antimitochondrial antibodies B. Problem with bilirubin conjugation C. Problem with bilirubin uptake D. Problem with excretion of conjugated bilirubin E. Problem with hepatic copper excretion
B. Problem with bilirubin conjugation The patient ha Crigler-Najjar syndrome type 1. Patients with this condition lack uridine diphosphate glucuronyl transferase, resulting in an inability to conjugate bilirubin. This leads to increased unconjugated bilirubin which causes jaundice, kernicterus, and bilirubin deposition in the brain. Crigler-Najjar syndrome type 1 manifests early in life and is fatal. Type 2 of the syndrome is less severe and responds to phenobarbital.
A 42 yo woman comes to the physician with severe itching that has lasted 4 days. Her PE is significant for hepatomegaly and 3 xanthomas on her right lower leg. Lab studies reveal a normal total bilirubin level and elevated serum cholesterol and alkaline phosphatase levels. Which of the following antibodies is most specific for this patient's condition? A. Anticentromere antibodies B. Antihistone antibodies C. Antimitochondrial antibodies D. Antinuclear antibodies E. Rheumatoid factor
C. Antimitochondrial antibodies In primary biliary cirrhosis (PBC), there is an inflammatory autoimmune attack of intrahepatic bile ducts. This leads to biliary obstruction and accumulation of cholesterol in the liver parenchyma. This patient most likely has PBC, a chronic autoimmune liver disorder that may initially present with fatigue, severe itching, hepatomegaly and xanthomas. Although hepatomegaly can be asymptomatic in these patients, episodes of pruritic often occur in response to tight-fitting clothing and warm weather. Jaundice and hyperbilirubinemia do not occur until the later stages of disease when the liver has become cirrhotic. The pathologic hallmark is granulomatous destruction of medium-sized intrahepatic bile ducts. Although the pathogenesis is unknown, >90% of the patients have elevated levels of antimitochondrial antibodies.
An obese 43 yo woman has epigastric discomfort, fever and scleral icterus of 2 days duration. PE reveals slight jaundice and right upper quadrant tenderness without peritoneal signs. There is no hepatosplenomegaly. The patient's history is significant for mild, intermittent epigastric pain after meals over the past several months. Lab tests show a WBC count of 14,200/mm3, with 74% segmented neutrophils, and a serum lipase level of 78 U/L (normal). Which of the following is the most likely diagnosis of this patient's acute symptoms? A. Acute pancreatitis B. Acute viral hepatitis C. Bacterial cholangitis D. Cholelithiasis E. Primary biliary cirrhosis
C. Bacterial cholangitis The Charcot classic triad of RUQ pain, jaundice and fever is typically found in patients with cholangitis. Patients may describe symptoms consistent with long-standing gallstones, such as abdominal pain after eating fatty foods. These gallstones could have blocked the bile duct, leading to infection. Bacterial cholangitis is defined as bacterial infection of the bile ducts. Cholangitis can result from any condition obstructing the bile flow, most commonly choledocholithiasis. The bacteria are usually enteric gram - rods (e. coli, kleb, bacteroides, or enterobacter) that enter the bile duct via the ampulla of Vater. Leukocytosis with neutrophilic and elevated band cell count is commonly present as well. In the setting of cholecystitis, the patient will present with persistent colicky RUQ pain and nausea but less often displays marked fever and leukocytosis, unless there is significant bacterial proliferation within the gallbladder.
A 20 yo black man is brought to his physician's office by his mother, who states that over the past year he has become depressed and withdrawn and at times has been paranoid and distrustful of family members. On PE he is found to have hepatomegaly and dark rings around his irises. He also has a slow, shuffling gait and on passive movement his arms move in a rigid jerky fashion. The mother mentions that her son's paternal grandmother had a similar condition. Which of the following medications is given to slow the progression of the disease? A. alpha-interferon B. Carbidopa-levodopa C. D-penicillamine D. Deferoxamine E. Lactulose
C. D-penicillamine Wilson's disease is an autosomal recessive disorder characterized by copper accumulation in the liver, brain, eye, kidney, and other organ systems. Patients usually present during childhood or adolescence, and manifestations of liver disease are the most common presenting symptoms. Copper deposits in the cerebral cortex lead to psychiatric symptoms such as personality changes, depression and even psychosis. Copper also builds up in the putamen, causing parkinsonian features such as bradykinsesia, suffering gait and cogwheel rigidity. Kayser-Flesher rings, which are copper deposits in the limbus of the cornea, are pathognomonic for Wilson's disease. The diagnosis is made by detecting low levels of drum ceruloplasm, increased hepatic copper content, and increased urinary excretion of copper. Treatment with D-penicillamine, a copper chelating agent, can dramatically slow the otherwise progressive end organ deterioration.
A 42 yo Jap who immigrated to the US 3 months ago present to the oncologist saying he was recently diagnosed with a cancer that is known to be aggressive. He then hands the slide to the oncologist (shows signet cells). What type of cancer does this histology most likely depict? A. Brain B. Breast C. Gastric D. Lung E. Ovarian
C. Gastric The histology image depicts a signet ring cell carcinoma. The mucin displaces the nuclei to the side, which makes the cell take on a ring-like appearance. Gastric cancer sometimes has this typical signet ring cell morphology.
A 28 yo females is hoping to have a baby, but has been unable to maintain a pregnancy. She has become pregnant twice over the past year, but both times have resulted in miscarriage. male and female infertility studies show no endocrine or anatomic abnormalities in her or her husband. A careful history reveals that she suffers from tennis elbow and peptic ulcer disease, both of which she actively treats. Which of the following medications will result in this woman's inability to maintain uterine implantation? A. Acetaminophen B. Indomethacin C. Misoprostol D. Omeprazole E. Ranitidine
C. Misoprostol Misoprostol is a prostaglandin-1 analog used to prevent NSAID induced peptic ulcers. It increases the production and secretion of the gastric mucus barrier as well as decreases the production of acid. This patient has a history of an inflammatory injury (tennis elbow), that she is currently being treated for, possibly with NSAIDs. Treatment with NSAIDs for pain relief from her tennis elbow will put this patient at a higher risk of acquiring an NSAID-induced ulcer, given the fact that she also has underlying peptic ulcer disease. Therefore, treatment with misoprostol is a reasonable option to lessen her risk of formation of an NSAID-induced ulcer. However, misoprostol is also an abortifacient and may cause birth defects and thus must be avoided in women of child-bearing age. It is likely that this patient has been prescribed misoprostol, which has been causing her miscarriages.
A 7 yo boy is brough tot the ED by his mother with a 2 day history of abdominal pain and four to five episodes of watery diarrhea a day. He also has a low-grade fever and feelings of nausea. On PE, there is epigastric tenderness on palpation. Upon further questioning, the patient's mother states he had an upper respiratory infection 2 weeks ago, which was treated with a completed course of ampicillin. The patient is otherwise healthy. Results of a toxin stool test are positive. Which of the following cells helps the body control this type of diarrheal disease? A. Brunner glands B. I cells C. Paneth granular cells D. Parietal cells E. S cells
C. Paneth granular cells This patient has most likely developed C. dif colitis secondary to ampicillin use. It can also be seen with clindamycin use and is typically treated with metronidazole or vancomycin. Paneth granular cells are in the small intestine and release a-defensins (antibacterial and anti fungal peptides as well as lysozymes.
A 42 yo man visits his PCP to discuss possible cholesterol lowering agents. His last blood tests revealed elevated LDL cholesterol and triglyceride levels. The physician decides to prescribe gemfibrozil, which the patient takes as prescribed for the next 6 months. If the medication is effective, which of the following results are likely to be seen on this patient's next blood test? A. A large decrease in LDL cholesterol, a small increase in HDL cholesterol and a small decrease in triglycerides B. A moderate decrease in LDL cholesterol with little to no effect on HDL or triglycerides C. A moderate decrease in LDL cholesterol, a slight increase in HDL cholesterol and a slight increase in triglycerides D. A small decrease in LDL cholesterol, a small increase in HDL cholesterol and a large decrease in triglycerides E. An increase in LDL cholesterol, a slight decrease in HDL cholesterol and a decrease in triglycerides
D. A small decrease in LDL cholesterol, a small increase in HDL cholesterol and a large decrease in triglycerides Gemfibrozil is a fabric acid derivative that acts on peroxisome proliferator-activated receptor alpha protein to increase the activity of lipoprotein lipase and facilitate enhanced clearance of triglycerides. It typically leads to a large decrease in triglycerides, a small reduction in LDL cholesterol and a small increase in HDL cholesterol.
A 26 yo male is brought to he physician because of chronic abdominal pain. He was adopted as an infant, and his parents know nothing of his biological family. His stool is positive for occult blood. Genetic analysis reveals an inherited autosomal dominant mutation on chr 5. A colonoscopy is performed and a representative image is shown here. Which of the following describes his condition? A. He has a 50% risk of developing colon cancer. B. His condition is characterized by skip lesions and submucosal edema with a cobblestone appearance. C. His condition is due to a mutation in DNA repair genes. D. His condition would be best managed with a complete colon resection. E. Sulfasalazine is an effective first-line treatment for this condition.
D. His condition would be best managed with a complete colon resection This patient has FAP, which is associated with mutation or deletions of the APC gene on chr 5. (5=5 letters in polyp). In this condition, thousands of polyps are present in the colon. The APC gene has important tumor suppressor function and FAP is inherited in an autosomal dominant fashion. Tumor formation is promoted when a "second hit" takes out the normal gene during development and cellular division. In FAP, patient are not for with polyps in their colon, but develop the precancerous growths shortly after puberty. The natural history of the disease involves a progression to adenocarcinoma of the colon, with a 100% incidence in untreated patients. The only effective treatment after diagnosis is a total colonic resection.
Scientists recently discovered a new drug for treating hypercholesterolemia. In vitro studies with a hepatocyte cell line revealed that the drug increases the number of LDL cholesterol receptors by acting in a manner similar to that of steroids. What is the mechanism by which this drug is acting on hepatocytes? A. Allosteric regulation B. Cell surface receptor antagonism C. G protein-cell receptor-mediated phosphorylation D. Hormone receptor complex formation E. Proteolytic modification
D. Hormone receptor complex formation Like steroid hormones, this drug binds to a cytosolic receptor to form a hormone receptor complex. The complex is transported to the nucleus, where it acts (as does a TF) on DNA to increase the transcription of LDL cholesterol receptor messenger RNA, which is translated into LDL receptors. It is important to note that both steroid and this drug are able to cross the phospholipid bilayer because of their lipophilicity.
An 8 yo boy is treated with IV antibiotic for 7 days as a result of a perforated appendix. Although he does well initially, at the end of his antibiotic course, he develops abdominal cramping and a temp of 103. He also experiences several episodes of watery diarrhea. Which of the following antibiotics should be used to treat this patient? A. Ampicillin B. Ceftriaxone C. Clindamycin D. Metronidazole E. Tetracyline
D. Metronidazole Pseudomembranous colitis is found primarily in hospitalized patients and is caused by C.dif. This organism causes diarrhea (usually water, but small amounts of blood may be present), abdominal cramping, and fever through the production of two exotoxin: toxin A and B. This infection usually manifests after a patient has been treated with broad-spectrum antibiotics for several days. The broad-spectrum antibiotic treatment shifts the balance of normal intestinal flora and allows C.dif to grow in abundance. Metronidazole is first-line. Vancomycin is second line
A 24 yo man presents to his PCP complaining of diarrhea, abdominal pain, weightless and intermittent fevers over the past 6 months. The patient also has eye pain, stiff joints, and a red skin rash on his shins. A barium enema demonstrates patchy terminal ileum involvement, fistulas and stenoses. The patient is also at risk for what other disease? A. Chronic amebic dysentery B. Irritable bowel syndrome C. Primary biliary cirrhosis D. Renal calculi
D. Renal calculi Crohn disease is a chronic, relapsing and remitting inflammatory condition. Although it may affect any part of the GI tract it most commonly involves the distal ileocecum, small intestine or colon. Involvement of the SI predisposes patients to a number of malabsorptive problems. Vitamin B12 absorption is often compromised, whereas oxalate absorption is enhanced, leading to an increased incidence of calcium oxalate renal calculi. Other extra intestinal manifestations of Crohns includes uveitis, migratory polyarthritis, and erythema nodosum. Although less than those with UC, Crohn's patients are still at increased risk of andeocarcinoma in the colon. The disease tends to affect young people int eh second and third decades of life and is seen most frequently in Jews. The barium enema results describe typical pathologic findings, which include cobblestone appearance of the mucosa, stenoses and fistulas as complications of the transmural nature of the disease. Involvement of the colon is usually patchy (skip lesions) as opposed to continuous, and the rectum is usually spared. Biopsies will show granulomas.
A 73 yo woman with a history of aortic valve replacement complain of indigestion associated with fatty foods. She looks pale and also notes several years of chronic fatigue. X-ray of the abdomen shows a cluster of nodular radio densities in the RUQ. Hematocrit: 29% Total bili: 3.3 mg/dL Indirect bili: 3.0 dg/mL Corrected reticulocyte count: 6% (high) **x-ray shows stones in the gall bladder Which of the following most likely constitutes the nodular radiodensities evident on this patient's film? A. Calcium oxalate B. Cholesterol C. Conjugated bilirubin D. Unconjugated bilirubin E. Uric acid
D. Unconjugated bilirubin Bilirubin is the product of heme metabolism. It is removed from blood by the liver, conjugated with glucuronate, and excreted in bile. When liver enzymes are overwhelmed with the amount of bilirubin available for processing, unconjugated bilirubin into the bile, causing supersaturation in the gallbladder over time, which can then precipitate as microscopic crystals. These microscopic crystals are aggregated gradually in the gallbladder mucus and become macroscopic gallstones.
A 50 yo man presents to his physician because of a 15lb weight loss over the past month, epigastric pain radiating to the back, and jaundice. He also complains of redness, swelling and tenderness of his left lower extremity. Labs show increased levels of amylase, lipase and alkaline phosphatase. Which tumor markers are most likely to be elevated in this patient? A. alpha-fetoprotein and beta-human chorionic gonadotropin B. alpha-fetoprotein and CA 19-9 C. alpha-fetoprotein and carcinoembryonic antigen D. beta-humanchorionic gonadotropin and carcinoembryonic antigen E. CA 19-9 and carcinoembryonic antigen
E. CA 19-9 and carcinoembryonic antigen This patient has s/s characteristic of pancreatic adenocarcinoma. This malignancy often presents with jaundice, epigastric pain radiating to the back and weight loss. The red, swollen, tender lower extremity indicates a possible deep vein thrombosis. Patients with pancreatic adenocarcinoma may present with migratory thrombophlebitis called Trousseau syndrome, in which thrombi appear and disappear in various parts of the body due to the hyper coagulable state induced by the pancreatic adenocarcinoma. Lab studies show increased amylase, lipase and alkaline phosphatase levels. Tumor markers such as CA 19-9 and CEA are often elevated in pancreatic cancer. Pancreatic cancers are more common in patients with a history of smoking, diabetes mellitus and chronic pancreatitis. Treatment for pancreatic adenocarcinoma is surgical removal.
A 24 yo man presents to the physician with profuse bloody diarrhea and abdominal cramps. On questioning, it is learned that the patient went swimming a lake during a camping trip 2 weeks earlier. A stool sample is sent for lab evaluation. Which of the following is most likely to be seen on microscopic examination of this patient's stool? A. Acid-fast staining cysts B. Macrophages containing amastigotes C. RBCs containing schizonts D. Tear-shaped trophozoites with two nuclei E. Trophozoites with ingested RBCs
E. Trophozoites with ingested RBCs This patient is infected with Entamoeba histolytica, which is transmitted via cysts in water (fecal-oral transmission). Infection presents with bloody diarrhea (dysentery), abdominal cramps with tenesmus, and pus in the stool. It can also cause right upper quadrant pain and liver abscesses. On microscopy one observes trophozoites (the amoeba) with ingested RBCs. Treatment for E. histolytica infection includes metronidazole and iodoquinol.
A 3 week old boy presents to his pediatrician because his mother has noticed that he "looks yellow". On questioning, she elaborates that the jaundice began several days after birth and has been associated with dark urine and clay-colored stools. Lab studies show a direct bilirubin level of 5 mg/dL and a total bilirubin level of 5.5 mg/dL. Which of the following is a characteristic of the most likely diagnosis? A. Caused by a genetic mutation in a promoter region B. Caused by a deficiency in uridine 5'-diphospho-glucuronosyltransferase C. Commonly treated with phototherapy D. Inherited disorder with impaired biliary excretion of conjugated bilirubin E. Untreated, it leads to cirrhosis by 6 months of age
E. Untreated, it leads to cirrhosis by 6 months of age. The patient is presenting with congenital extra hepatic biliary atresia. Descriptions of a pure elevation in direct (conjugated) bilirubin strongly suggest an obstructive cause, as the liver is able to effectively conjugate bilirubin but fails to excrete it into the small intestine. The absence of bilirubin in the small bowel results in acholic stools, whereas increased renal excretion of conjugated bilirubin causes a darkening of the urine. Congenital extra hepatic biliary atresia occurs when the developing bile ducts close completely and fail to recanalize. Surgical therapy of biliary atresia involves anastomosis of the small bowel directly to intrahepatic bile ducts, a maneuver known as the Kasai procedure, which is appropriate for the 10% of patients with limited disease. Liver transplant continues to be the best chance of survival for the remaining patients. Without surgical intervention to recanalize bile ducts, retained bile int he liver inevitably results in cirrhosis and eventually liver failure.
A 27 yo accountant presents to his physician 5 weeks after returning from a trip to his grandfather's home in rural India, where he lived with locals. He is jaundiced and complains of n/v, fever and abdominal pain. he denies any new sexual contacts and has never used recreational drugs. He has no significant medical history. Hepatomegaly is noted on exam. His lab values show elevated ALT, AST and bilirubin. What is the genomic structure of the virus most likely causing this patients symptoms? A. Double-stranded linear DNA B. Double-stranded linear RNA C. Double-stranded partially circular DNA D. Single-stranded circular RNA E. Single-stranded linear DNA F. Single-stranded linear RNA
F. Single-stranded linear RNA Hep E is the most likely cause of this patient's disease, though hepatitis A is also a possibility. Both are single-strafed linear RNA viruses transmitted via the fecal-oral route that are endemic in developing countries. Given the history of travel to rural India and the geographic distribution of hepatitis viruses (HEV is the most common hep infection in the developing world), HEV is the most likely. The incubation period following exposure to HEV is 3-8 weeks, with a mean of 40 days. Infection with HAV and HEV si often characterized by jaundice and systemic symptoms in adults, although asymptomatic infection does occur. Children with HAV are usually asymptomatic. Lab finding include elevated aminotransferases (ALT>AST) and increases in bilirubin. Recovery ensues within a few months, with no risk of chronic disease except for HEV in immunocompromised hosts. There is no indicated medical treatment beyond supportive care. HAV is part of the picornavirus family and HEV is part of the herpesvirus family.
A 35 yo woman presents to the ED because of abdominal pain and diarrhea mixed with mucus and blood. She also has ulcerated lesions with violaceous borders on her legs. Gross blood is present on rectal exam. A biopsy specimen of her colon reveals inflammation confined to the mucosa and submucosa. Which of the following would most likely be used to treat this patient? A. Infliximab B. Nizatidine C. Omeprazole D. Ondansetron E. Sucralfate F. Sulfasalazine
F. Sulfasalazine This patent has ulcerative colitis. The leg lesions represent pyoderma gangrenosum and are the first clue of an extra-intestinal manifestation of UC. The diagnosis is confirmed with the biopsy specimen, showing that the inflammation is contained to the mucosal and the submucosal layers. Sulfasalazine is a combination of sulfapyridine, which is an antibacterial drug, and melamine, which is an anti-inflammatory drug. Its adverse effects include malaise, nausea, sulfonamide toxicity and reversible oligospermia. This is the first-line agent for treating UC.
A 31 yo man comes to a GI for a complete work-up after experiencing bouts of unexplained rectal bleeding, pain in his abdomen and diarrhea. A flexible sigmoidoscopy is performed and the result shows lots of colonic "bumps". The patient is counseled that his son and daughter must also be evaluated in the future. The patient was lost to follow-up but returns to clinic 5 years later with similar yet more severe symptoms. The patient undergoes another sigmoidoscopy and a biopsy specimen is obtained which is found to be malignant. Which of the tumor suppressor/oncogene gene pairs are most likely representative of the mutations present in this patient's tumor? A. APC/KRAS B. APC/p53 C. BRAF/APC D. p53/APC E. APC/BCR-ABL
A. APC/KRAS This patient has familial adenomatous polyposis (FAP), an autosomal dominant condition leading to adenomatous polyps within the colonic mucosa. These patients are more prone to develop colon cancer due to the large number of polyps present, each with potential for malignant transformation. FAP is caused by a mutation the APC tumor suppressor gene on chr. 5. FAP is an example of the two-hit hypothesis in which malignancy only develops when a second mutation occurs that results in a loss of heterozygosity in a tumor suppressor gene. In this case, patients with FAP inherit a mutation in the APC gene, putting them at increased risk of developing a second mutation int eh remaining normal allele. When this occurs, it leads to polyp overgrowth. Additional mutations in other key tumorigenesis genes ultimately leads to transformation of the polyps. In this case, one of the first mutations that leads to transformation of the polyps. In this case, one of the first mutations that lead toward malignancy is the oncogene KRAS. Non mutated KRAS is important for normal cellular signaling and acts as a GTPAse. When mutated KRAS protein activity is uncontrolled and signaling pathways become dysregulated.
A pediatrician is called in to evaluate an infant who has not been able to feed at all since birth. HIs mother reports that every time she tries to breastfeed him, the infant chokes and coughs. The mother denies any use of alcohol or drugs during pregnancy. She also denies any history of STDs. She says that her pregnancy and delivery were uneventful, but remembers the obstetrician being concerned about excess amniotic fluid seen on her ultrasound. Which of the following is most likely to be seen on the infant's x-ray of the chest? A. Air in the stomach B. Herniation of the stomach, spleen and intestines C. Lung hypoplasia D. Pleural effusion E. Widened mediastinum
A. Air in the stomach This infant is manifesting signs of the most common type of tracheoesophageal fistula: a tracheoesophageal fistula with esophageal atresia. In these infants, there is an abnormal division of the respiratory and esophageal tracts int eh 4th week of gestation. This leads to the upper esophagus emptying into the distal portion of the trachea. In utero, this abnormality prevents the infant from swallowing amniotic fluid. This is what results in polyhydraminos for the mother, which is seen as excess amniotic fluid on ultrasound. Once the child is born, the atresia prevents swallowing, causing spillage of formula into the trachea (with resultant choking and aspiration) from the blind-ended esophagus. The fistula also causes air to fill the stomach when the infant breathes. A large stomach air bubble would therefore be expected on this infant's chest radiograph.
A 24 yo student presents with RUQ pain, nausea, and occasional vomiting. She says she recently returned from a camping trip to Australia, where she interacted with many animals, including dogs, wallabies, and kangaroos. PE reveals an enlarged liver, and ultrasound imaging shows a 2cm liver cyst. Which of the following is the most appropriate management.? A. Albendazole B. Diethylcarbamazine C. Observation D. Praziquantel E. Surgical drainage
A. Albendazole Echinococcus granulosus is a parasitic tapeworm transmitted by the feces of animals such as dogs, wallabies and kangaroos. Infection can result in liver cysts. The contents of the cysts may cause anaphylactic shock if exposed to the immune system. First-line treatment is albendazole. Albendazole acts by inhibiting tubule polymerization in the tapeworm. It is quite a toxic drug, commonly causing abnormal liver function tests and (rarely) causing a variety of cytopenias and renal failure. Cysts that are less than 5 cm can be treated with albendazole alone.
A 78 yo man has a 3 day history of diarrhea, LLQ pain and slight fever. He reports that there was a small amount of blood in his stool earlier in the day, but denies any long-term bleeding. Labs reveal a leukocyte count of 14, a hematocrit level of 0.35 and platelet count of 250. His BMI is 31. The resident physician suggests a colonoscopy to rule-out colon cancer, however, the attending physician points out that this procedure is contraindicated, given the most likely diagnosis in this patient. What is the most likely anatomical location of this patient's condition? A. Attenuated muscularis propria B. Dilated submucosal varices C. Invaginated mesenteric tissue D. Lymphoid tissue in mucosa
A. Attenuated muscularis propria The patient described in the question stem has symptoms of diverticulitis. This is an inflammation of diverticula, often in the sigmoid colon. Its related to retention of material within a diverticulum and fecalith formation. Diverticulitis typically manifests as LLQ pain with fever, anorexia, and diarrhea. Its often associated with a slightly increased leukocyte count, and anemia can be present if the patient has bleeding. It's diagnosed with a CT scan and colonoscopies are contraindicated because of the risk of perforation. Diverticula occur when pressure causes herniation of the colonic wall through its own muscularis propria usually in the sigmoid colon. Occasionally, a diverticulum may cause rupture of a nutrient artery where it penetrates the muscularis propria; this results in bright red painless bleeding from the rectum.
A 36 yo woman with a family history of HNPCC presents to her gastroenterologist for her annual examination. Because of a strong family history of colon cancer, she undergoes yearly colonoscopy. However, she has shown no signs and symptoms of HNPCC and has no significant past medical history. Other than colorectal carcinoma, what is another condition for which she is at increased risk given a family history of HNPCC? A. Carcinoma of the endometrium B. Cholelithiasis causing cholecystitis C. Melanin spots of the buccal mucosa D. Pseudopolyps of the small or large bowel E. Vitamin B12 deficiency due to malabsorption
A. Carcinoma of the endometrium HNPCC, also known as Lynch syndrome, is a rare autosomal dominant disorder associated with an increased incidence of colorectal cancer. Generally, the syndrome is associated with mismatch repair. Approximately 70% of people with the syndrome will develop colorectal cancer, typically at 40-45 years of age. Also, there is a high risk of extracolonic cancer, including endometrial, ovarian, urinary tract, small intestine, stomach, and biliary cancer. As a result, high-risk patients begin annual screening colonoscopies at age 20-25 years, or 10 years before the age of the youngest diagnosed family member. Women >35 years old typically undergo annual endometrial biopsy due to the high risk of endometrial carcinoma.
A middle-aged woman is found dead in an alley. It appears that she died recently, as the body has not yet decomposed. Autopsy reveals no signs of trauma, and the internal organs are intact. After several hours of investigation, the pathologist believes a clue to a possible cause of death is present in her liver. The specimen shows mallory bodies. What is her contributing cause of death? A. Chronic alcohol abuse B. Cocaine overdose C. Fulminant viral hepatitis D. Pregnancy-related fatty liver E. Pulmonary failure related to alpha1-antitrypsin deficiency
A. Chronic alcohol abuse Mallory bodies (twisted rope) and neutrophilic infiltrate are consistent with hepatitis seen in chronic exposure to alcohol. Mallory bodies are intracytoplasmic hyaline inclusions derived from cytokeratin intermediate filaments and are also commonly seen in primary biliary cirrhosis, Wilson disease, chronic cholestatic syndromes, and hepatocellular tumors.
A 22 yo woman presents with dyspnea upon exertion, weakness and fatigue. On PE, she has hair loss, spoon-shaped fingernails and pale mucous membranes. She has a history of heavy menstrual bleeding. Lab results reveal RBC count of 2 million/mm3, mean corpuscular volume of 65 fL (normal), and mean corpuscular hemoglobin of 24 pg (low). Malabsorption in what part of the gastrointestinal tract will produce the type of anemia described in the stem? A. Duodenum B. Gastric fundus C. Ileum D. Jejunum E. Sigmoid colon
A. Duodenum One of the causes of microcytic anemia is iron deficiency. Iron is absorbed in the duodenum via two independent mechanism. Heme-associated iron is taken up by a heme transporter in the luminal plasma membrane of the duodenal epithelial cell. Free ferric iron ions (Fe3+) are converted to ferrous iron ions (Fe2+) by a cytochrome B enzyme on the luminal plasma membrane of the duodenal epithelial cell. Ferrous iron ions are taken up by the divalent metal transporter channel, also in the luminal plasma membrane. Within the cell, iron is transferred to mucosal ferritin and then shuttled to transferrin in the plasma. Although some iron absorption may occur int eh upper jejunum, most of it occurs in the duodenum. Thus, a deficiency in duodenal absorption will cause iron deficiency, which is the most common cause of microcytic anemia. Iron efficiency may lead to decreased mean corpuscular hemoglobin (MCH), which is the average amount of hemoglobin per RBC in a blood sample.
An elderly man presents to his PCP complaining of chronic diarrhea and new-onset shortness of breath. Physical exam reveals a flushed complexion, contender abdomen, and a new onset holosystoloic murmur on the left sternal border at the 4th intercostal space. Stool is guaiac negative. What medication could alleviated his symptoms most effectively? A. B2 agonist B. Amoxicillin C. Inhaled corticosteroids D. Octreotide E. Sulfasalazine
D. Octreotide The patient is presenting with carcinoid syndrome, which is due to an active carcinoid tumor secreting large amounts of serotonin. Excessive serotonin production leads to bronchospasm (via activation of smooth muscle in the bronchioles), diarrhea, and tricuspid valve degradation. Left sided valvular disease is not usually seen because lung tissue metabolizes serotonin. Treatment of this disease usually requires surgery, although octreotide can be used to alleviate symptoms. Octreotide will bind somatostatin receptors located on tumor cells, preventing the release of serotonin.
A 46 yo man presents to the ED complaining of severe abdominal pain following a weekend of tailgating during which he consumed a "ton" of beer. On PE the patient has a temp of 100.8, with pain located in the epigastric region that periodically radiates to his back. Lab tests show a serum amylase level of 400 U/L and WBC count of 16,000/mm3. What is the most likely complication of this disease? A. Cholecystitis B. Chronic gastritis C. Pancreatic carcinoma D. Pancreatic pseudocyst E. Small bowel obstruction
D. Pancreatic pseudocyst This patient's presentation is classic for acute pancreatitis. This process often occurs in young patients after consuming large amounts of alcohol. Other causes include gallstone obstruction, medication, infection, hypertriglyceridemia and trauma. Pseudocysts often arise after a bout of acute pancreatitis and consist of necrotic, hemorrhagic debris with pancreatic enzymes. These cysts lack a true epithelial lining.
A 26 yo woman with HCV is being seen because she wants to be treated. Her cousin was treated about 5 years ago. One of the drugs her cousin was taking caused him to have fevers and chills and a sense of depression that he did not have prior to treatment. Your patient wants to avoid these side effects. Which of the following drugs was the cause of the cousin's adverse effects? A. IV immunoglobulin B. Lamivudine C. Ledispasvir/sofosbuvir D. Pegylated interferon E. Ribavirin F. TNF alpha
D. Pegylated interferon Interferon alpha is a cytokine that decreases viral replication and increases the host immune response. The pegylated form has a longer half-life, being given weekly instead of 3x/week. Interferon alpha was used for many years in the treatment of HCV, initially alone and later in combination with ribavirin. It is now being replaced by simple, once daily, oral regimens with fewer side effects. Interferon-alpha is also used int he treatment of selected cases of Hep B like when there is already evidence of an immune response (lower viral load and aminotransferase elevation indicated immune-mediated injury. Adverse effects of interferon therapy include flu-like reaction that manifests as fevers and chills, as well as depression, which an be profound, with suicidal ideation. As a result, interferon-alpha is contraindicated in severely depressed or suidcidal patients. In a small fraction of patients, pegylated interferon-alpha plus ribavirin was able to cure chronic Hep C, demonstrated by no detectable virus 6 months after completion of a 6 month treatment regimen.
A novel drug is developed that specifically acts only on the intestinal epithelium. This new drug is found to prevent the absorption of glucose and galactose from the lumen, but does not affect the absorption of fructose. Based on the new drug's effects, which of the following is the most likely mechanism of action? A. It targets insulin regulation of glucose transporters B. It targets the GLUT2 transporter C. It targets the GLUT4 transporter D. It targets the GLUT5 transporter E. It targets the NaK pump within intestinal cells
E. It targets the NaK pump within intestinal cells Fo monosaccharides such as glucose, galactose and fructose to be absorbed after ingestion, they need to first pass through the apical side of the GI epithelium and then again through the basolateral side of the epithelium into the blood. The apical side of the GI epithelium has numerous microvilli with numerous dedicated transporters. Both glucose and galactose traverse the apical membrane by the action of SGLT1. SGLT1 is a symporter, in that it simultaneously transports sodium and either monosaccharide into the cell. It is able to draw these monosaccharides into the epithelial cells along with sodium because of the sodium gradient created by the NaK ATPase at the basolateral membrane. Fructose on the other hand, traverses the apical epithelial membrane via a sodium-independent monosaccharide transport (GLUT-5). After glucose, galactose and fructose enter the epithelial cells of the SI, they all travers the basolateral membrane into the bloodstream via GLUT2. A medication that would inhibit the absorption of glucose and galactose, but not fructose would have to work by inhibiting the absorption of glucose and galactose at the apical membrane. Inhibition of the SGLT1 symporter could be achieved by impairing the sodium gradient establish by the basolateral NaK ATPase, which helps drive these monosaccharides into the cell.
The image shows the gross pathology of a congenital abnormality that results from incomplete obliteration of the omphalomesenteric (vitelline) duct. This pathological structure is usually found protruding from tissues derived from what source? A. Dorsal mesentery B. Foregut C. Hindgut D. Mesonephric duct E. Midgut F. Neural crest cells
E. Neural crest cells The vignette image shows a Meckel diverticulum, the result of the persistence of a portion of the vitelline duct. This manifests as a blind pouch that protrudes from the ileum. The ileum is derived from the midgut, a portion of the primitive gut tube that gives rise to the intestinal tract from the distal duodenum to the proximal 2/3s of the transverse colon. Mickey diverticulum is characterized by the rule of 2s: it's 2 inches long, 2 feet from the ileocecal valve, occurs in 2% of the population, presents in the first 2 years of life. Mickey diverticulum may contain ectopic tissues such as gastric and pancreatic epithelium, which are derived from foregut. Occasionally, acid secreted from the gastric mucosa in a Meckel diverticulum may cause local ulceration and bleeding.
A 10 yo boy with an X-linked immunodeficiency disease suffers from chronic recurrent GI inflammation, which only moderately improves cyclosporine therapy. The child has had previous lab evaluation that showed a negative reaction to the nitroblue tetrazolium test. The patient's father wants to know how his son can have both an immunodeficiency disease and an autoimmune disease. Which of the following immune components is most likely impaired in this child? A. Antibodies B. IgA C. IgM D. Lysosomes E. Neutrophils
E. Neutrophils Chronic Granulomatous Disease (CGD) is a disorder in which neutrophils are unable to completely eradicate certain phagocytosed bacteria and fungi. As a result, the chronic immune response to these lingering pathogens leads to the development of self-tissue damage. NADPH oxidase, which is found in the membranes of phagosomes, is integral to the formation of reactive oxygen species like superoxide that are necessary to degrade phagocytosed pathogens. Consistent failure to clear these pathogens leads to unregulated inflammation, which explains why 50% of patients with CGD suffer a chronic gut inflammation that is similar to Crohns.
A 65 yo woman presents to her doctor because of weakness, light-headedness, peripheral neuropathy, a recent 10lb weight loss and diarrhea. She has a past medical history of hypothyroidism. A CBC is significant for a hemoglobin of 7.5 g/dL, hematocrit at 28% and a high mean corpuscular volume. This patient is most likely deficient in a substance produced by which of the following types of cells? A. Chief cells B. G cell C. I cell D. Mucous cell E. Parietal cell
E. Parietal cell The vignette describes symptoms of anemia with some GI effects which should make one suspicious of pernicious anemia. Anemia is confirmed by the low hematocrit and hemoglobin levels, and the elevated mean corpuscular volume indicates that is a microcytic anemia. A common cause of microcytic anemia is vitamin B12 and/or folate deficiency. This patient is also experiencing neurologic symptoms and while both vitamin B12 and folate deficiencies cause microcytic anemia, only vit B12 deficiency causes neurologic deficits. One cause of vit B12 deficiency is pernicious anemia. It is an autoimmune condition that can cause decreased production of intrinsic factor (which is required for B12 absorption) or reduced function
A 48 yo man complains of 4 weeks of profuse diarrhea. In the last week, he has developed lethargy and muscle weakness. On PE, his mucous membranes appear dry, his neck veins are flat, and he has reduced skin turgor. A CT scan of the abdomen reveals a 3cm mass on the tail of the pancreas. What is one of the direct physiologic functions of the hormone that is being secreted from this patient's pancreatic mass? A. Decreases insulin release B. Increases gastric acid secretion C. Increases gastric mixing D. Increases insulin release E. Relaxes intestinal smooth muscle
E. Relaxes intestinal smooth muscle The patient has a VIPoma, a pancreatic mass secreting vasoactive intestinal peptide. This hormone is normally secreted from parasympathetic ganglia throughout the GI tract. Its functions include increased secretion of water and electrolytes into the intestinal lumen, and relaxation of intestinal smooth muscle and sphincters. VIPomas are rare tumors and are most commonly found in the tail of the pancreas. The excess secretion results in profuse watery diarrhea, hypokalemia, and hypochlorhydria (Verner-Morrison syndrome). Generally, by the time these tumors are symptomatic, they can be seen on CT. Prognosis varies based on the size of the tumor and metastasis but median survival is 9-10 years. Symptoms can be alleviated with octreotide, a somatostatin analog that opposes the actions of VIP, and surgical reception may be warranted in some cases.
A 15 yo boy from Finland comes to the physician complaining of diarrhea, flatulence, and foul-smelling stools. He also reports easy fatiguability and weakness. On physical exam he appears pale and thin. CBC reveals iron deficiency anemia. A jejunal biopsy is shown in the image. This condition is also most likely associated with which of the following findings? A. Ascending weakness B. Frequent bloody stool C. Hyperpigmented skin lesions D. Painful swelling of large joints E. Small clusters of fluid-filled papule and vesicles
E. Small clusters of fluid-filled papule and vesicles The vignette describes a classic case of celiac sprue, which tends to occur in those of Northern European descent. Intestinal biopsy reveals villous blunting, crypt hyperplasia and lymphocytic infiltration into the lamina propria. Celiac sprue is associated with dermatitis herpetiformis, so names because the lesion cluster in a manner similar to those of herpes and is characterized by groups of pruritic papular and sometimes bulls lesions located symmetrically on the trunk and extensor surfaces.
A 19 yo man comes to the ED with a penetrating stab wound to the upper right back. The patient is hypotensive and has decreased breath sounds on the right side. A chest tube is placed and drains 1.5 L of bloody fluid; the patient is taken to the OR for thoracotomy. Initial CT of the abdomen showed no abnormalities, and there was no intestinal perforation. During this time, the patient requires large amounts of IV fluids, blood replacement, and medications to maintain his BP. The next day, he becomes severely acidotic and complains of intense abdominal pain. PE reveals a soft and non distended abdomen. His abdominal pain most likely originates from damage to which of the following structures? A. Cecum B. Hepatic flexure, large bowel C. Ileum D. Jejunum E. Splenic flexure, large bowel F. Stomach
E. Splenic flexure, large bowel Given the patient's history of hypotension, followed by development of acidosis, ischemic bowel is the most likely cause of his abdominal pain (rather than traumatic injury). The patient also demonstrated pain out of proportion to his normal PE findings, which is classically associated with ischemic bowel. The splenic flexure of the large bowel is most vulnerable to ischemia from hypo perfusion because it lies at the junction of two vascular territories: SMA and IMA. This would be more common than an area without a watershed area due to anastomosis. The patient in this scenario develops acidosis because of ischemia, leading to an anaerobic metabolism and resulting in the production of lactic acid.
A worried mother brings her 2 yo daughter to the clinic. She states that, as she was changing her daughter's diaper, she noticed brick-red-colored stools. On PE, the child is well appearing and playful. She has normal bowel sounds. The abdomen is soft, contender and non distended with no guarding or rebound. A Tc scan reveals an abnormality in the right lower quadrant. What is the embryologic origin that causes the child's symptoms? A. Neural crest cells B. The foregut C. The handgut D. The urachus E. The vitelline duct
E. The vitelline duct An area of ectopic gastric mucosa int eh RLQ is consistent with Meckel diverticulum. The acid produced from the ectopic gastric mucosa can cause lower GI tract ulceration and bleeding, resulting in hematochezia seen in the patient. The presentation is often otherwise unremarkable. Mickey diverticulum is a remnant of the omphalomesenteric (vitelline) duct, an embryologic structure that connects the midgut to the yolk sac. Normally, it obliterates during the seventh week of development. Because the ileocecal valve is derived from the midgut, it stands to reason that Meckel diverticulum generally manifests as a mass in either R quadrants.
A 44 yo man presents to his physician for evaluation of a 1 year history of enlarging breast tissue. PE is significant for spider telangietasias on his face; also his abdomen is distended but contender, with dullness to percussion and a positive fluid wave. The patient mentions that he has a family history of a paternal grandmother who developed hyper pigmentation, type 1 diabetes mellitus, and liver disease in her late 50s. Liver biopsy shows micro nodular cirrhosis. This disease process is due to a derangement of which of the following processes? A. Ceruloplasmin synthesis in the liver B. Collagen synthesis around central veins C. Phagocytosis of iron by macrophages D. Secretion of alpha 1 antitrypsin by the liver E. Transfer of iron from mucosal cells to plasma transferrin
E. Transfer of iron from mucosal cells to plasma transferrin Hereditary hemochromatosis is an autosomal-recessive disorder of the HFE gene, resulting in unrestricted absorption of iron from the GI tract, increasing the saturation of transferrin. Iron is deposited in the liver, pancreas, heart, joints, skin, and pituitary, stimulating the production of free radicals that cause tissue damage and fibrosis. Clinically hemochromatosis presents with cirrhosis secondary to iron deposition in hepatocytes and bronze diabetes secondary to destruction B islet cells in the pancreas, and increased melanin production and iron deposition in the skin. Treatment is typically ongoing phlebotomy to remove blood from circulation.
A 6 yo boy is brought to the urgent care center by his mother. She states that he has no known medical problems and has been ill let week with a cold and headache, but these symptoms resolved with bed rest and OTC medications. She believed her son was feeling better, but states that he was nauseated and had vomited the previous day. This morning, she states, the boy seems very sleepy and confused, and also appears a bit yellow. Which of the following is commonly associated with the most likely cause of this patient's jaundice? A Complete absence of 5'-diphosphoglucuronosyltransferase B. Conjugated hyperbilirubinemia and grossly black liver C. Decreased intrahepatic 5'-diphosphoglucuronosyltransferase D. Defective hepatic excretion of bilirubin E. Transiently impaired metabolism of fatty acids by hepatic mitochondria
E. Transiently impaired metabolism of fatty acids by hepatic mitochondria This patient's presentation is consistent with Reye syndrome, a disorder of fatty infiltration of the liver that is associated with impaired mitochondrial metabolism of fatty acids. It occurs in children and usually follow a viral illness such as cause by varicella or influenza virus that was treated by aspirin administration. Symptoms may include abrupt onset of nausea and vomiting, followed by encephalopathy and jaundice. Although the mother did not offer information regarding aspirin use, the physician should inquire further, given the patient's presentation. Inhibition of B-oxidation, the catabolic process whereby fatty acids are metabolized, is done in a dose=dependent and reversible manner. When the body is cleared of aspirin, inhibition ceases, but the toxic effects may linger if treatment is not initiated until a more advanced stage.
