Chapter 27 Hematologic Disorders and Oncologic Emergencies

In children with severe SCA, what drug is used to reduce number of painful crises and incidences of acute chest syndrome?

Hydroxyurea

After12 months of age, Cow's milk should be limited to how much per day?

24 ounces per day

Medical Management of DIC (3)

Prevention Maintain organ perfusion PRBC's if indicated

In a sick, febrile child with isolated thrombocytopenia, petechiae, or purpura, the major diagnosis to consider first is what?

*Meningococcemia* (infection caused by the Neisseria meningitidis bacteria. This is the same type of bacteria that can cause meningitis)

What lab diagnostic values are typically seen in TEC?

+ Anemia + *markedly* low Reticulocyte count + MCV is normal + PLT normal or elevated + High serum iron level + Erythroid hyperplasia on bone marrow aspiration

What are the most common manifestation in children with NHL? (2)

1. *Acute abdomen* - including abd pain, distention, fullness and constipation 2. Nontender lymph node enlargement

A lead blood level greater then what is concerning for public health purposes?

10

At what age does 95% of Adult hemoglobin?

12 months

Universal hemoglobin screening should be done at which age?

12 months

Exclusively breast-fed infants should be started on iron supplementation when?

4 months

How long after starting Iron supplementation should the patient follow up?

4 weeks *if there's adequate response, IDA is confirmed*

What is "ANC" in relation to lab values and what does its number influence? (lecture)

Absolute Neutrophil Count Influences choice of chemo drugs

The typical laboratory findings of *Hemophilia* are what?

A normal PT and PFA and an *abnormal* aPTT (PFA = platelet function analyzer)

A client is assessed in the oncology clinic following the administration of chemotherapy the previous week. Blood work reveals that the client is neutropenic, necessitating hospitalization. In caring for this client, the nurse would anticipate: A. Restricting fresh salad, raw fruits and uncooked vegetables in the diet. B. Administrating epoetin alpha (Epogen) every other day. C. Providing alcohol based mouthwash to be used after meals and before bed. D. Avoiding intramuscular injections and venipunctures. (quiz)

A. Restricting fresh salad, raw fruits and uncooked vegetables in the diet

A nurse is administering a chemotherapeutic medication to a client, who reports generalized itching and then chest tightness and shortness of breath. The nurse immediately.... A. Stops the chemotherapeutic infusion B. Administers diphenhydramine C. Places the client on oxygen by nasal cannula D. Gives prednisolone IV (prep-U)

A. Stops the chemotherapeutic infusion Rationale: The client may be experiencing a type I hypersensitivity reaction, which may progress to systemic anaphylaxis.

Effects of radiation therapy on Bone Marrow (symptoms) (3) hint: Think about the cells that are made in bone marrow. Wouldn't they be killed off? If so, what conditions would that cause? (book question)

Anemia Leukopenia Thrombocytopenia

Development of new blood vessels induced by growth factors or cytokines which may be produced by tumors or inflammation; Also called neovascularization hint: New vessels are "generated"

Angiogenesis

Common GI symptoms of radiation toxicity (4) (book question)

Anorexia Nausea Vomiting Diarrhea

Which three other tests are helpful in identifying patients with multiple prothrombic risk factors? (3)

Antiphospholipid antibodies Elevated fasting homocysteine levels Elevated factor VIII (8)

Nursing care, restrictions, and safety precautions related to a patient undergoing radiation therapy (6) hint: Where is the patient's room? Will there be a sign on the door? What kind of visitors are allowed and for how long? Should they come close to the patient? (book question)

Assigning the patient to a private room Posting appropriate notices about radiation safety precautions Pregnant staff members should not be assigned to this patient Visits by children or pregnant visitors should be prohibited Limit visits to 30 minutes daily Visitors maintain a 6-foot distance from the radiation source

When should lead screenings be done?

At 9 to 12 months and again at 24 months

Why does ferritin have to be interpreted carefully?

Because it is going acute phase reaction and maybe increase with inflammatory conditions

The nurse is evaluating bloodwork results of a patient with cancer who is receiving chemotherapy. The patient's platelet count is 60,000/mm3. Which of the following is an appropriate nursing action? A. Providing patient with a razor to shave B. Avoiding use of products containing aspirin C. Providing commercial mouthwash to patient D. Taking patient's temperature rectally (prep-U)

B. Avoid aspirin Rationale: Patients with a platelet count of 60,000/mm3 are at mild risk for bleeding. Appropriate nursing interventions include avoiding use of products such as aspirin that may interfere with the patient's clotting systems; avoiding taking temperature rectally and administering suppositories; providing patient with an electric shaver for shaving; and avoiding commercial mouthwashes due to their potential to dry out oral mucosa, which can lead to cracking and bleeding

After completing the first of bimonthly chemotherapy treatment for colorectal cancer, the nurse shares the laboratory results with the client's physician. The physician orders filgrastim (Neupogen) for three days. The nurse explains to the client that the medication: A. Should be taken on an empty stomach for best absorption. B. Can be self-administered at home. C. Will be administered on 3 consecutive days prior to the next chemotherapy. D. Is expected to improve the client's anemia within two weeks.

B. Can be self-administered at home. Rationale: Filgrastim, a medication that stimulates WBC production, can be self-administered at home. It must be stored in the refrigerator, and should be removed one hour prior to administration to allow it to warm to room temperature. The vial is for one dose only, and the client should be instructed to discard the vial after each dose and not to save any unused medication. Administration of filgrastim is parenteral (intravenous or subcutaneous). Filgrastim cannot be used orally, because it is a protein. Proteins are destroyed in the gastrointestinal tract. The therapy should start no sooner than 24 hours after chemotherapy administration. Therapy can continue up to 2 weeks after chemotherapy induced nadir. Epogen is used for anemia

Delivery of radiation therapy through internal implants (seeds are implanted) (mentioned in class)

Brachytherapy

What type of antineoplastic agent is 5-fluorouracil (5-FU) classified as? A. Nitrosourea B. Hormonal agent C. Antimetabolite D. Antitumor antibiotic

C. Antimetabolite

The nurse at the clinic explains to the patient that the surgeon will be removing a mole on the patient's back that has the potential to develop into cancer. The nurse informs the patient that this is what type of procedure? A. Diagnostic B. Palliative C. Prophylactic D. Reconstructive

C. Prophylactic Rationale: Prophylactic surgery involves removing nonvital tissues or organs that are at increased risk of developing cancer. When surgical cure is not possible, the goals of surgical interventions are to relieve symptoms, make the patient as comfortable as possible, and promote quality of life as defined by the patient and family. Palliative surgery and other interventions are performed in an attempt to relieve complications of cancer, such as ulceration, obstruction, hemorrhage, pain, and malignant effusions (Table 15-6). Reconstructive surgery may follow curative or radical surgery in an attempt to improve function or obtain a more desirable cosmetic effect. Diagnostic surgery, or biopsy, is performed to obtain a tissue sample for histologic analysis of cells suspected to be malignant

What needs to be monitored every few months in SCA?

CBC and Reticulocyte count

What labs are indicated for NHL?

CBC w/ diff CMP Lactate Dehydrogenase Uric Acid

Three step cellular process of transforming normal cells into malignant cells

Carcinogenesis

Type of therapy that involves the use of antineoplastic drugs in an attempt to destroy cancer cells by interfering with cellular functions, including replication and DNA repair; May be combined with surgery or radiation

Chemotherapy

What diagnostic studies should be done for NHL suspicion?

Chest Xray Ultrasound CT or MRI PET scan Bone marrow aspirate LP w/ CNS fluid analysis

Cancer management is aimed at what 3 treatment goals?

Cure Control Palliation

When caring for a client who is receiving external beam radiation, which is the key point for the nurse to incorporate into the plan of care? A. Avoid showering or washing over skin markings. B. Time, distance, and shielding C. The use of disposable utensils and wash cloths D. Inspect the skin frequently. (prep-U)

D. Inspect the skin frequently Rationale: Inspecting the skin frequently will allow early identification and intervention of skin problems associated with external radiation therapy. The external markings should not be removed, but clients may shower and lightly wash over the skin. Time, distance, and shielding are key in the management of sealed, internal radiation therapy and not external beam radiation. The use of disposable utensils and care items would be important when caring for clients following systemic, unsealed, internal radiation therapy.

When the client complains of increased fatigue following radiotherapy, the nurse knows this is most likely to be related to which factor? A. The cancer cells are dying in large numbers B. Fighting off infection is an exhausting venture C. The cancer is spreading D. Radiation can result in myelosuppression. (Prep-U)

D. Radiation can result in myelosuppression Rationale: Fatigue results from anemia associated with myelo suppression and decreased RBC production. The spreading of cancer can cause many symptoms dependent on location and type of cancer but not a significant factor to support fatigue with radiotherapy. The production of healthy cells can increase metabolic rate, but death of cancer cells does not support fatigue in this case. Fighting infection can cause fatigue, but there is no evidence provided to support presence of infection in this client.

Megaloblastic anemias are due primarily to a lack of?

Folic acid & Vitamin B12 (or both)

A nurse is caring for a client receiving chemotherapy. Which assessment finding places the client at the greatest risk for an infection? A. White blood cell (WBC) count of 9,000 cells/mm3 B. Ate 75% of all meals during the day C. Temperature of 98.3° F (36.8° C) D. Stage 3 pressure ulcer on the left heel (prep-u)

D. Stage 3 pressure ulcer on left heel Rationale: Stage 3 pressure ulcer is a break in the skin's protective barrier, which could lead to infection in a client who is receiving chemotherapy

A client received chemotherapy 24 hours ago. Which precautions are necessary when caring for the client? A. Wear sterile gloves. B. Place incontinence pads in the regular trash container. C. Provide a urinal or bedpan to decrease the likelihood of soiling linens. D. Wear personal protective equipment when handling blood, body fluids, and feces. (prep-U)

D. Wear PPE Rationale: Chemotherapy drugs are present in the waste and body fluids of clients for 48 hours after administration. The nurse should wear personal protective equipment when handling blood, body fluids, or feces. Gloves offer minimal protection against exposure.

What is the probable diagnosis if the PT and aPTT are ELEVATED in association with thrombocytopenia?

DIC

Cells are most vulnerable to the disruptive effects of radiation during ___ ____________ and mitosis. (Book question)

DNA synthesis

Common signs/symptoms of HIT (5)

DVT Angina Dyspnea Thirst Headache

Nursing management of HIT (3)

Decrease heparin exposure Observe for complications Patient education

What medication is used for chelation of iron stores?

Deferasirox Deferoxamine

The treatment for von Willbrance disease (vWF) is what?

Desmopressin (DDAVP) and Factor VIII vWF concentrates

Wide spread coagulation cascade caused commonly by damage to the endothelium

Disseminated Intravascular Coagulation (DIC)

What results are commonly seen with megaloblastic anemia?

Elevated MCV (>100) Blood smear showing nucleated RBCs & macroovalocytes with anisocytosis and poikilocytosis + normal WBC and PLT + Large and hyperhsegmented Neutrophils + thrombocytopenia or possibly Large platelets

Most commonly used form of radiation

External Beam Radiation Therapy (assumingly due to its non-invasive properties)

What are the most common inherited thrombophilia diseases? (5)

Factor V Leiden Prothrombin 20210 mutation Antithrombin deficiency Protein C deficiency Protein S deficiency

True or False: Primary cancer prevention involves detection and screening to achieve early diagnosis and intervention.

False Secondary Prevention is aimed at detection and screening; Primary is aimed at reducing risk

what are the two different types of hemoglobin?

Fetal-hgb (Hgb - F) Adult-hgb (Hgb - A)

Monoclonal antibodies (MoAbs) mimic the antibodies your body naturally produces as part of your immune system's response to germs, vaccines and other invaders. What are the most common side effects of most all MoAbs? (4)

Fever Chills Fatigue Anorexia/General Malaise

Treatment for Hyponatremia in SIADH (2) (1 restriction; 1 administration)

Fluid restriction (800-1000 mL/day) Administer hypertonic 3% saline infusion

Vesicant chemotherapy should NEVER be administered in peripheral veins involving the ______ or ______. Why?

Hand Wrist Increased risk of extravasation

What are the diagnostic findings seen in sickle cell disease?

Hct of 20 to 29% Hgb 6 to 10 (severe) Reticulocyte count elevated (5 to 15%) Nrml to incrsd WBC & PLT counts MCV > 80 & MCHC > 37 Hgb electrophoresis - Hgb S

The two most commonly used screening test for iron deficiency Are what?

Hemoglobin and hematocrit

Confirmation of hemolytic anemia is diagnosed from what?

Hemoglobin electrophoresis, Heinz body stain, and osmotic fragility test

Sickle cell disease describes a group of complex, chronic disorders characterized by what?

Hemolysis unpredictable acute complications that may become life threatening +possible development of chronic organ damage

What should be expected in cases of an elevated Reticulocyte count in the absence of bleeding or heparin therapy?

Hemolytic anemia

The development of thrombocytopenia (platelets less than 100,000), due to the administration of various forms of heparin

Heparin Induced Thrombocytopenia (HIT)

The most common causes of neutropenia in an acute febrile illness are?

Hepatitis A and B Epstein-Barr virus Cytomegalovirus

What is found on diagnostic labs with iron deficiency anemia?

Hgb - 8 to 11 MCV - Less than 60 Reticulocyte count - Low or slightly elevated

What are the Lab findings for Aplastic anemia?

Hgb - may be low MCV - elevated in *fanconi anemia* Retic count - LOW PLT & WBC - LOW

Iron deficiency anemia is most likely when a child has which lab value?

Hgb that is low for age (less than 8-11)

Palifermin (Kepivance) may be used during chemotherapy to treat stomatitis. What 2 therapies may be used complimentary to Palifermin? hint: Think of normal everyday household things you would eat to soothe the throat (Dynamed question)

Honey Cyrotherapy (Ice Chips)

Metabolic disturbances associated with Tumor Lysis Syndrome (4)

Hyperuricemia Hyperkalemia Hyperphosohatemia Hypocalcemia

What is the most common of all thrombocytopenia purpuras?

ITP - idiopathic thrombocytopenia purpura

What is given to patients with active severe bleeding and who cannot have steroids in ITP?

IVIG

3 most common biopsy methods

Incisional (wedge of tissue is removed for biopsy) Excisional (removal of entire tumor) Needle Biopsy (aspiration of cells)

3 stages of Carcinogenesis

Initiation (mutations caused in DNA) Promotion (repeated exposure to promoting agents leading to mutated genes) Progression (cells become malignant)

Substances that are essential for Red Blood Cell formation include? (4)

Iron Vitamin B12 Folic acid amino acids

What is often a comorbid condition associated with iron deficiency?

Lead poisoning

What is aplastic anemia?

Leukopenia, Thrombocytopenia, and Anemia

What are the lab findings with ITP?

Low Platelet counts Normal PT and aPTT Megathrombocytes on peripheral smear Normal WBC & RBC counts

Leading type of cancer in the United States

Lung Cancer

What type of anemia is *Megaloblastic Anemia*?

Macrocytic anemia

Phenomenon of abnormal cells that have invasive characteristics and infiltrate other tissues; Malignant cells spread from primary tumor to other cells through lymphatic or blood circulation

Metastasis

What is an important nursing intervention for Tumor Lysis Syndrome in a patient receiving chemotherapy?

Meticulous monitoring of renal function and hydration status Rationale: Some chemotherapy agents can damage the kidneys because they impair water secretion, leading to syndrome of inappropriate secretion of antidiuretic hormone (SIADH), decrease renal perfusion, precipitate end products after cell lysis, and cause interstitial nephritis

Chronic and genetic inflammatory condition in which the shape of RBC's are abnormal, causing decreased oxygen carrying capacity and vasoocclusion when stressors are triggered

Sickle Cell Anemia

What kind of Anemia is *Iron deficiency anemia*?

Microcytic hypochromic

What is the typical lab value Profile for IDA?

Microcytic, hypo chromic RBCs Low or normal MVC High RDW Low Ferritin High TIBC Mentzer index > 13

What is Non-Hodgkin Lymphoma?

NHL is a diverse group of solid tumors of the lymphatic tissues that form from malignant proliferation of *T cells, B cells, or indeterminate lymphocyte cells*

Lowest point of white blood cell depression after therapy that has toxic effects on the bone marrow

Nadir

What type of anemia is *Aplastic Anemia* under?

Normocytic anemia

3 common drugs used in the treatment of chemotherapy related nausea/vomiting

Ondansetron Reglan Emend

For frequent or prolonged chemotherapy administration, what routes should be used? (3)

PICC lines Art Lines Implanted venous access devices

Antimetabolites (5-FU) and antitumor antibiotics are the major culprits in mucositis and other gastrointestinal symptoms (stomatitis). What can be used to treat stomatitis?

Palifermin (Kepivance) rationale: Palifermin promotes epithelial cell repair and accelerated replacement of cells in the mouth and gastrointestinal tract. (pg 345)

Type of care centered on the relief of symptoms associated with the disease and improvement of quality of life at any disease stage

Palliative Care

Common clinical manifestations (signs/symptoms/lab values) of DIC (5)

Peripheral Cyanosis Ischemia (if untreated) Bleeding/hemorrhage Hematuria Increased Coagulation Studies (D-Dimer/Platelets/PT/aPTT)

What are the physical findings for aplastic anemia?

Petechiae, purpura Infection Multiple anomalies

What symptoms may a child have when they are Iron deficient/anemic?

Pica (appetite for paper, dirt, and clay) Pagophagia (desire to eat Ice) Anorexia

Surgical treatment in Cancer may be used for tumor removal, biopsy, and diagnosis, but can also be used for ____________. hint: Angelia Jolie

Prevention

Although most RBC disorders result in a decreased quantity of cells or cell abnormalities, it is important not to forget the congenital, though rare, proliferative disorder called?

Primary Polycythemia (polycythemia rubra vera)

Primary vs. Secondary Cancer Prevention

Primary: Concerned with reducing cancer risk in healthy people; Lifestyle/Diet changes/Avoid carcinogens Secondary: Involves detection and screening (mammogram/testicular exam)

What is the earliest marker for IDA?

RDW (High)

Type of cancer treatment therapy that may be used to cure, control, or be palliative; 60% of patients receive this at some point during treatment; Can be used to kill cancer cells

Radiation Therapy

The youngest RBCs are called?

Reticulocytes

A nurse caring for an adult patient who develops a mild oral yeast infection following chemotherapy should encourage the patient to do what?

Rinse mouth with normal saline

What should be done before any treatment for Alpha-thalassemia is begun?

Serum iron studies should be done before starting any iron supps. because of the risk of iron overload in thalassemia

Cancer treatment options and prognosis are based on a tumors _________ and __________.

Stage Grade

What should be done the age of the child in the dietary patterns are consistent with iron deficiency and there is microcytic anemia (hgb < 9)?

Start a trial of iron supplementation for 4 to 6 weeks without further diagnostic and another inpatient Life at this moment

Disorder of the oral cavity that is commonly associated with some chemotherapy agents because of the rapid turnover of epithelium that lines the oral cavity.

Stomatitis

Facial Plethora (excess of blood in the face) causes redness and swelling in what oncologic emergency?

Superior Vena Cava Syndrome (SVC)

Tumor suppressor gene that may be mutated in cancer

TP53

In this condition, there is anemia and increased erythropoiesis - the erythropoiesis results in bone marrow expansion.

Thalassemia

Diminished production of one of the two subunit chains of hemoglobin (alpha and beta) results in disorders called?

Thalassemias

Dietary iron is absorbed throughout the intestine but especially in where?

The duodenum

Chemotherapy administration patient education points (3)

The importance of adhering to prescribed self-administered premedication before presenting to the infusion center Recognizing and reporting the signs and symptoms to the nurse once the infusion has started. Reporting s/s that may occur at home

In an Implanted vascular access device, what must the nurse always do when accessing a port? (book/lecture)

Use a Huber needle Rationale: The self-sealing septum permits repeated puncture by Huber needles without damage or leakage.

Patients receiving internal radiation emit radiation while the implant is in place; therefore, contact with the health care team is guided by principles of _______, ___________, and ___________ to minimize exposure of personnel to radiation.

Time Distance Shielding

True or False The lethal tumor dose of radiation is defined as that which will eradicate 95% of the tumor yet preserve normal tissue.

True

Tumor stages and grading is done through TNM Classification. What does TNM stand for?

Tumor (extent of) Nodes (are they metastasized) Metastasis (absence/presence of distant metastasis)

Syndrome referring to a variety of metabolic disturbances that may be seen in the treatment of cancer; Occurs when a large number of neoplastic cells are killed/ "lysed"

Tumor Lysis Syndrome

Oncologic Emergencies (7) (slides)

Tumor Lysis Syndrome DIC SIADH Spinal Cord Compression Superior Vena Cava Syndrome (SVC) Hypercalcemia Pericardial effusion and Cardiac Tamponade

ITP is usually cause from what?

Usually occurs after viral illness + in many cases, the cause is autoimmune

TEC frequently follows which condition?

Viral illness

What conditions are included in Megaloblastic Anemias?

Vitamin b12 deficiency Folate deficiency

Physical findings of megaloblastic anemia relate to the severity but commonly include what? (2)

Weakness & pallor *Beefy-red, smooth, sore mouth and tongue*

What is Glucose-6-Phoshate Dehydrogenase Deficiency?

a drug-induced hemolytic anemia can be caused from G6PD enzyme in the RBC. + Sx's are generally associated w/ infections or exposure to oxidant metabolites of certain drugs that cause precipitation of Hgb, injury to RBC, and rapid hemolysis.

Megaloblastic anemia should be expected if there is any history of young infants who are?

being fed a diet of powdered cow's milk products or *goat milk*

What is Hereditary Spherocytosis (HS)?

characterized by a deficiency or abnormality of the RBC membrane protein spectrum, which reduces the RBC surface area.

Pancytopenia is marked by what?

decrease in all three formed elements of the blood - *erythrocytes, leukocytes, and platelets*

What is found on diagnostic labs with Megaloblastic Anemia?

decreased Hgb Elevated - *MCV* Low - Retic count Low - PLT & WBC

In thalassemias, the bone marrow expansion results in?

frontal bossing and hyperplasia of the maxillary bones leading to typical facies

Megaloblastic anemias develop if what occurs?

if diet lacks folic acid and B12 OR if the gastric intrinsic factor necessary for B12 is absent

The primary diagnostic feature of Beta-thalassemia is what?

increased Adult-hgb that is > 3.5% on electrophoresis

Children with Beta-thalassemia need to be closely monitored for?

iron overload.

What is the management of TEC?

it is self limited, with recovery taking place 1 to 2 months after Dx

What does transferrin do?

it transport iron to the bone marrow and uno the maturing RBC, where it incorporated into the new heme molecule.

What are the clinical findings associated with HS?

jaundice usually appears in newborns (may be difficult to differentiate HS from hyperbilirubinemia caused by ABO incompatibility) + After 2 years old, splenomegaly is usually present. + Chronic fatigue, malaise, and abdominal pain may also be noted.

What are the clinical findings for a patient with a thalassemia trait?

most are symptomatic, although some may have mild pallor and splenomegaly. + Hgb level of 9.5 to 11 + Hct less than 30% + MCV of less than 75 + Mentor index of iron is usually > 13

Lymphocytosis is produced by viral illnesses including what?

mumps, measles, rubella, varicella, mono and hepatitis

What is the management for G6PD?

no specific Tx is available.

What is Transient Erythroblastopenia of Childhood (TEC)?

occurs in first year of life + characterized by *Anemia, reticulocytopenia and erythroid hypoplasia of bone marrow*

What is commonly found on physical exam in G6PD?

pallor and jaundice (w/ chronic hemolysis)

Parents can be taught to assess what?

palpate the Spleen *Any downward displacement or enlargement of spleen below the left costal margin needs eval from a PCP & blood counts monitored for increasing anemia*

What lab test can diagnosis the spherical HS?

peripheral blood smear

What is the diagnostic testing done for G6PD?

several dye reduction tests provide diagnosis *screening should be done 2-3 months after an episode*

What is the treatment of choice for children with severe HS requiring multiple transfusions?

splenectomy (with removal of the gallbladder) - *produces a clinical cure* (should be deferred until 6 years old)

What happens in HS?

the RBC membranes assume a more spherical shape *Hence RBCs are more likely to be sequestered and prematurely destroyed in the spleen*

What happens in Beta-thalassemia *major*?

the alpha-chains do not bind with each other but rather degrade in the absence of beta-chains.

What occurs in Alpha-thalassemia?

the beta-globulin subunits cluster into groups of four in the absence of any alpha-chains with which to partner. *These beta-tetramers are incapable of carrying oxygen, and the affected fetuses die in utero*

What happens in Beta-thalassemia *minor*?

there are sufficient Beta-chains present to bind with the abundant alpha-chains to create functional Hgb molecules and a resultant *asymptomatic mild microcytic anemia*

What is Leukemia?

when normal bone marrow elements are replaced with *abnormal, poorly differentiated lymphocytes called BLAST CELLS*