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ABIM Hematology study materials
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ABIM Hematology practice questions

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Question 1Patient care and procedural skills

A 24-year-old woman has iron deficiency anemia. Which laboratory finding best distinguishes iron deficiency anemia from anemia of chronic disease?

  1. Elevated total iron-binding capacity
  2. Low serum ferritin Correct answer.
  3. Low serum iron
  4. Normal or elevated serum ferritin

Explanation

Ferritin reflects body iron stores and is the most specific single test for iron deficiency; a low ferritin in an anemic patient confirms depleted stores. In anemia of chronic disease ferritin is typically normal or elevated because it is an acute-phase reactant.

Question 2Patient care and procedural skills

Which finding on the peripheral smear is most characteristic of hereditary spherocytosis?

  1. Basophilic stippling
  2. Schistocytes
  3. Bite cells
  4. Spherocytes with increased mean corpuscular hemoglobin concentration Correct answer.

Explanation

Loss of membrane surface area in hereditary spherocytosis produces round, dense spherocytes and a raised mean corpuscular hemoglobin concentration. Schistocytes and bite cells reflect different hemolytic mechanisms.

Question 3Patient care and procedural skills

A patient with suspected pernicious anemia is being evaluated. Which test most directly confirms the autoimmune cause?

  1. Serum vitamin B12 level
  2. Peripheral blood smear
  3. Anti-intrinsic factor antibodies Correct answer.
  4. Serum methylmalonic acid

Explanation

Anti-intrinsic factor antibodies are highly specific for pernicious anemia and directly demonstrate the autoimmune mechanism blocking B12 absorption. B12, methylmalonic acid, and smear findings establish deficiency or its metabolic consequences but not the cause.

Question 4Patient care and procedural skills

Which coagulation abnormality is expected in a patient with severe liver disease?

  1. Isolated prolonged partial thromboplastin time
  2. Shortened bleeding time with elevated factor VIII
  3. Prolonged prothrombin time and partial thromboplastin time Correct answer.
  4. Prolonged prothrombin time with normal partial thromboplastin time

Explanation

The liver synthesizes most clotting factors, so impaired synthetic function prolongs both the prothrombin time and the partial thromboplastin time. Factor VII has the shortest half-life, so the prothrombin time often rises first, but severe disease affects both pathways.

Question 5Patient care and procedural skills

A patient with acute promyelocytic leukemia develops diffuse bleeding shortly after presentation. Which abnormality most likely underlies the bleeding?

  1. Immune thrombocytopenia
  2. Disseminated intravascular coagulation Correct answer.
  3. Factor VIII inhibitor
  4. Vitamin K deficiency

Explanation

Acute promyelocytic leukemia releases procoagulant material that triggers disseminated intravascular coagulation, producing bleeding with consumption of platelets and fibrinogen. Rapid initiation of all-trans retinoic acid addresses the coagulopathy.

Question 6Patient care and procedural skills

Which laboratory pattern is most consistent with a diagnosis of disseminated intravascular coagulation?

  1. Elevated fibrinogen with normal D-dimer
  2. Isolated prolonged partial thromboplastin time with normal platelets
  3. Low platelets, low fibrinogen, elevated D-dimer Correct answer.
  4. Elevated platelets with prolonged bleeding time

Explanation

Disseminated intravascular coagulation consumes platelets and fibrinogen while generating fibrin degradation products, so thrombocytopenia, hypofibrinogenemia, and elevated D-dimer occur together. Prolonged clotting times accompany these changes.

Question 7Patient care and procedural skills

A young man has recurrent venous thrombosis and a personal history of a similar event in a sibling. Which inherited thrombophilia is most strongly associated with this presentation?

  1. Antithrombin deficiency
  2. Factor V Leiden mutation Correct answer.
  3. Prothrombin gene mutation
  4. Protein C deficiency

Explanation

Factor V Leiden is the most common inherited thrombophilia and confers resistance to activated protein C, predisposing to venous thrombosis. Family history and young age at first event support inherited thrombophilia testing.

Question 8Patient care and procedural skills

A patient on warfarin has an INR of 8.5 with no bleeding. Which intervention is most appropriate?

  1. Start a direct oral anticoagulant immediately
  2. Continue warfarin and recheck in one week
  3. Give fresh frozen plasma
  4. Hold warfarin and give oral vitamin K Correct answer.

Explanation

For a markedly elevated INR without bleeding, warfarin is held and low-dose oral vitamin K is given to reverse the anticoagulant effect. Fresh frozen plasma is reserved for serious bleeding or emergent procedures.

Question 9Patient care and procedural skills

Which finding is most consistent with immune thrombocytopenia in an otherwise healthy adult?

  1. Pancytopenia with hypocellular marrow
  2. Isolated thrombocytopenia with a normal peripheral smear apart from reduced platelets Correct answer.
  3. Elevated D-dimer and low fibrinogen
  4. Schistocytes and elevated lactate dehydrogenase

Explanation

Immune thrombocytopenia causes isolated low platelets with an otherwise unremarkable smear; large platelets may be seen but other lineages are normal. Pancytopenia or microangiopathic findings point to other diagnoses.

Question 10Patient care and procedural skills

A patient with chronic myeloid leukemia is being treated with imatinib. Which molecular target does this drug inhibit?

  1. BTK
  2. JAK2
  3. FLT3
  4. BCR-ABL tyrosine kinase Correct answer.

Explanation

Imatinib inhibits the BCR-ABL tyrosine kinase produced by the Philadelphia chromosome in chronic myeloid leukemia. Monitoring for molecular response guides therapy.

Question 11Patient care and procedural skills

Which peripheral blood finding is characteristic of chronic lymphocytic leukemia?

  1. Auer rods in myeloblasts
  2. Pelger-Huët anomaly
  3. Numerous mature-appearing small lymphocytes with smudge cells Correct answer.
  4. Tear drop cells with myelofibrosis

Explanation

Chronic lymphocytic leukemia shows a clonal expansion of mature small lymphocytes, and fragile cells produce smudge cells on the smear. Immunophenotyping confirms the diagnosis.

Question 12Patient care and procedural skills

A patient with multiple myeloma presents with fatigue and bone pain. Which laboratory finding is most typical?

  1. Low total protein with low globulin gap
  2. Monoclonal protein spike with suppressed uninvolved immunoglobulins Correct answer.
  3. Isolated thrombocytosis
  4. Elevated alkaline phosphatase with normal calcium

Explanation

Multiple myeloma is characterized by a monoclonal immunoglobulin spike with suppression of normal immunoglobulins, contributing to infection risk. Bone pain reflects lytic lesions, often with hypercalcemia.

Question 13Patient care and procedural skills

A patient with sickle cell disease has a painful vaso-occlusive crisis. Which initial management is most appropriate?

  1. Hydroxyurea started during the acute crisis
  2. Aggressive intravenous hydration and prompt opioid analgesia Correct answer.
  3. Immediate splenectomy
  4. Routine red cell exchange transfusion for every crisis

Explanation

Acute vaso-occlusive crisis is managed with aggressive hydration and timely opioid analgesia, along with treatment of triggers. Transfusion is reserved for severe complications such as acute chest syndrome or stroke.

Question 14Patient care and procedural skills

Which test is used to screen for von Willebrand disease?

  1. Factor VIII activity alone
  2. Bleeding time alone
  3. Platelet aggregation with ADP
  4. Von Willebrand factor antigen and ristocetin cofactor activity Correct answer.

Explanation

Screening for von Willebrand disease relies on von Willebrand factor antigen and ristocetin cofactor activity, often with factor VIII levels. These quantify the protein and its functional activity.

Question 15Patient care and procedural skills

A patient has a prolonged partial thromboplastin time that corrects with mixing with normal plasma. What does this indicate?

  1. Heparin contamination
  2. A factor deficiency Correct answer.
  3. A circulating inhibitor
  4. Lupus anticoagulant effect

Explanation

Correction of a prolonged partial thromboplastin time after mixing with normal plasma indicates a factor deficiency, because normal plasma supplies the missing factor. Failure to correct suggests an inhibitor.

Question 16Patient care and procedural skills

Which finding is most consistent with a diagnosis of essential thrombocythemia?

  1. Markedly elevated platelet count with normal marrow architecture and no other cause Correct answer.
  2. Schistocytes with thrombocytopenia
  3. Monoclonal protein spike
  4. Pancytopenia with fatty marrow

Explanation

Essential thrombocythemia is a myeloproliferative neoplasm with sustained thrombocytosis unexplained by reactive causes, often with JAK2 or CALR mutations. Marrow examination helps exclude other causes.

Question 17Patient care and procedural skills

Which patient is at highest risk for tumor lysis syndrome after starting chemotherapy?

  1. A patient with low-grade follicular lymphoma and small nodal burden
  2. A patient with chronic lymphocytic leukemia and stable counts
  3. A patient with Burkitt lymphoma and bulky disease Correct answer.
  4. A patient with essential thrombocythemia

Explanation

Tumor lysis syndrome is most likely in rapidly proliferating, bulky hematologic malignancies such as Burkitt lymphoma. Prophylaxis with hydration and monitoring of electrolytes and uric acid is indicated.

Question 18Patient care and procedural skills

A patient receiving heparin develops a falling platelet count. Which test is most appropriate to confirm heparin-induced thrombocytopenia?

  1. Platelet aggregation with ristocetin
  2. Serotonin release assay Correct answer.
  3. Mixing study
  4. D-dimer

Explanation

The serotonin release assay is a functional test that detects heparin-dependent antibodies activating platelets, confirming heparin-induced thrombocytopenia. Enzyme immunoassay is used for screening but is less specific.

Question 19Patient care and procedural skills

Which supportive measure is most important in preventing complications in a neutropenic patient after chemotherapy?

  1. Strict avoidance of all oral medications
  2. Prophylactic platelet transfusions regardless of count
  3. Prompt empiric broad-spectrum antibiotics for fever Correct answer.
  4. Routine granulocyte transfusions

Explanation

Fever in a neutropenic patient requires prompt empiric broad-spectrum antibiotics because infection can progress rapidly. Platelet transfusions are given for low counts or bleeding, not routinely in all patients.

Question 20Patient care and procedural skills

A patient with iron overload from repeated transfusions is being considered for chelation. Which agent is an oral iron chelator used for this purpose?

  1. Dimercaprol
  2. Deferasirox Correct answer.
  3. Penicillamine
  4. Deferoxamine

Explanation

Deferasirox is an oral iron chelator used to treat transfusional iron overload. Deferoxamine is also an iron chelator but requires parenteral administration.

Question 21Patient care and procedural skills

Which blood product should be used to correct a coagulopathy caused by warfarin in a patient with active major bleeding?

  1. Packed red cells alone
  2. Cryoprecipitate alone
  3. Prothrombin complex concentrate plus vitamin K Correct answer.
  4. Platelet concentrate

Explanation

Major bleeding on warfarin is treated with prothrombin complex concentrate for rapid factor replacement plus intravenous vitamin K. This restores the vitamin K-dependent factors quickly.

Question 22Patient care and procedural skills

A patient is being evaluated for a bleeding disorder and has a normal platelet count, normal prothrombin time, and normal partial thromboplastin time but a history of mucocutaneous bleeding. Which additional test is most useful?

  1. Platelet function testing Correct answer.
  2. Factor IX activity
  3. Antithrombin activity
  4. D-dimer

Explanation

Normal screening coagulation tests with mucocutaneous bleeding suggest a platelet function disorder, so platelet function testing is the next step. Standard coagulation assays do not assess primary hemostasis adequately.

Question 23Patient care and procedural skills

Which finding suggests a diagnosis of hemochromatosis in a patient with fatigue and joint pain?

  1. Low ferritin with elevated total iron-binding capacity
  2. Normal iron studies with elevated platelets
  3. Elevated transferrin saturation with elevated ferritin Correct answer.
  4. Low transferrin saturation with low ferritin

Explanation

Hereditary hemochromatosis produces increased iron absorption, leading to high transferrin saturation and elevated ferritin with progressive iron deposition. Confirmatory testing includes genetic testing for HFE mutations.

Question 24Patient care and procedural skills

A patient with a known factor VIII deficiency is scheduled for surgery. Which approach best guides perioperative factor replacement?

  1. Rely on the partial thromboplastin time alone
  2. Measure factor VIII activity and target a level appropriate for the procedure Correct answer.
  3. Give a fixed dose regardless of baseline level
  4. Withhold all factor replacement unless bleeding occurs

Explanation

Perioperative management of hemophilia requires measuring factor activity and replacing to a target level based on the invasiveness of the procedure. Trough levels are monitored to maintain hemostasis.

Question 25Patient care and procedural skills

Which condition is associated with a microangiopathic hemolytic anemia and thrombocytopenia in a patient with normal renal function and neurologic symptoms?

  1. Iron deficiency anemia
  2. Immune thrombocytopenia
  3. Warm autoimmune hemolytic anemia
  4. Thrombotic thrombocytopenic purpura Correct answer.

Explanation

Thrombotic thrombocytopenic purpura causes microangiopathic hemolytic anemia, thrombocytopenia, and neurologic findings due to ADAMTS13 deficiency. Prompt plasma exchange is the treatment of choice.

Question 26Patient care and procedural skills

A 24-year-old woman has a hemoglobin of 7.8 g/dL, MCV 72 fL, and a ferritin of 6 ng/mL. She has heavy menstrual bleeding. Which finding on peripheral smear is most expected?

  1. Macrocytic ovalocytes
  2. Spherocytes
  3. Microcytic hypochromic red cells Correct answer.
  4. Schistocytes

Explanation

Iron deficiency produces impaired hemoglobin synthesis, so erythrocytes are small (low MCV) and poorly hemoglobinized (hypochromic) with central pallor. Low ferritin confirms depleted iron stores, and heavy menses is a classic cause in reproductive-age women.

Question 27Patient care and procedural skills

A 68-year-old man has fatigue and early satiety. Examination shows massive splenomegaly. CBC shows leukoerythroblastosis with teardrop cells. Bone marrow biopsy is hypercellular with reticulin fibrosis. Which diagnosis is most likely?

  1. Essential thrombocythemia
  2. Acute lymphoblastic leukemia
  3. Chronic myeloid leukemia
  4. Primary myelofibrosis Correct answer.

Explanation

Primary myelofibrosis is characterized by marrow fibrosis with extramedullary hematopoiesis, producing massive splenomegaly, leukoerythroblastosis, and teardrop cells on smear. Reticulin fibrosis on biopsy supports this diagnosis.

Question 28Patient care and procedural skills

A 30-year-old woman has fatigue and jaundice. Labs show hemoglobin 8.2 g/dL, reticulocytes 12%, indirect hyperbilirubinemia, and a positive direct antiglobulin test. Which is the most appropriate first-line therapy?

  1. Corticosteroids Correct answer.
  2. Rituximab
  3. Splenectomy
  4. Plasma exchange

Explanation

A positive direct antiglobulin test with hemolysis and reticulocytosis indicates warm autoimmune hemolytic anemia, for which corticosteroids are first-line therapy. Splenectomy and rituximab are reserved for refractory or relapsing disease.

Question 29Patient care and procedural skills

A 55-year-old man with treated lymphoma has a platelet count of 8,000/µL and oozing from venipuncture sites. He has no schistocytes, and coagulation studies are normal. Which is the most appropriate immediate management?

  1. Platelet transfusion Correct answer.
  2. Cryoprecipitate transfusion
  3. Fresh frozen plasma transfusion
  4. Desmopressin administration

Explanation

Severe thrombocytopenia with mucosal bleeding in the absence of microangiopathy or coagulopathy indicates a platelet production problem, and platelet transfusion is indicated for clinically significant bleeding. The normal coagulation studies make plasma products unnecessary.

Question 30Patient care and procedural skills

A 60-year-old woman is started on high-dose dexamethasone as part of myeloma therapy. She has diabetes and is on insulin. Which prophylactic measure most directly reduces her risk of a serious complication of this regimen?

  1. Proton pump inhibitor therapy
  2. Trimethoprim-sulfamethoxazole prophylaxis Correct answer.
  3. Anticoagulation with aspirin
  4. Pneumococcal vaccination alone

Explanation

High-dose corticosteroids combined with myeloma-related immunosuppression markedly increase the risk of Pneumocystis jirovecii pneumonia, so prophylaxis with trimethoprim-sulfamethoxazole is standard. This directly prevents an opportunistic infection that can be fatal.

Question 31Patient care and procedural skills

A 45-year-old man with cirrhosis has a prolonged INR of 2.4 and platelets of 70,000/µL, but he is not bleeding. He requires an elective diagnostic paracentesis. Which is the most appropriate approach?

  1. Give recombinant factor VIIa before the procedure
  2. Proceed with the procedure without prophylactic blood products Correct answer.
  3. Transfuse fresh frozen plasma to normalize the INR before the procedure
  4. Transfuse platelets to a count above 100,000/µL before the procedure

Explanation

The INR reflects the severity of liver synthetic dysfunction rather than a bleeding tendency in cirrhosis, and routine paracentesis can be performed safely without correcting abnormal coagulation studies. Prophylactic products are not indicated for this low-risk procedure.

Question 32Patient care and procedural skills

A 35-year-old man has a hematocrit of 60% and a platelet count of 900,000/µL. He has aquagenic pruritus and splenomegaly, and testing shows a JAK2 mutation. Which diagnosis is most likely?

  1. Polycythemia vera Correct answer.
  2. Essential thrombocythemia
  3. Secondary polycythemia
  4. Primary myelofibrosis

Explanation

Markedly elevated hematocrit with thrombocytosis, aquagenic pruritus, splenomegaly, and a JAK2 mutation is characteristic of polycythemia vera. The JAK2 mutation supports a clonal myeloproliferative neoplasm rather than a reactive process.

Question 33Patient care and procedural skills

A 28-year-old woman has a platelet count of 25,000/µL, schistocytes on smear, elevated LDH, and a creatinine of 2.1 mg/dL. She has fever and neurologic changes. Which is the most appropriate immediate therapy?

  1. Platelet transfusion
  2. Plasma exchange Correct answer.
  3. Corticosteroids
  4. Eculizumab

Explanation

Microangiopathic hemolytic anemia with thrombocytopenia, renal impairment, and neurologic symptoms indicates thrombotic thrombocytopenic purpura, and urgent plasma exchange is the standard initial treatment. Delay increases mortality.

Question 34Patient care and procedural skills

A 70-year-old man with atrial fibrillation has a CHA2DS2-VASc score of 5 and requires long-term anticoagulation. He has severe renal impairment with a creatinine clearance of 20 mL/min. Which anticoagulant is most appropriate?

  1. Rivaroxaban
  2. Dabigatran
  3. Apixaban Correct answer.
  4. Edoxaban

Explanation

Apixaban has the most favorable profile in severe renal impairment among the direct oral anticoagulants and is the preferred agent when creatinine clearance is low. It can be dose-adjusted and has less renal clearance than dabigatran.

Question 35Medical knowledge

A 28-year-old woman has a hemoglobin of 7.8 g/dL, MCV 68 fL, and a ferritin of 6 ng/mL. Which of the following is the most appropriate next step in management?

  1. Erythropoietin administration
  2. Vitamin B12 supplementation
  3. Oral iron replacement Correct answer.
  4. Corticosteroid therapy

Explanation

Microcytic anemia with a low ferritin is diagnostic of iron deficiency anemia, and oral iron is first-line therapy for most patients. Ferritin is an acute-phase reactant, but a value this low is essentially pathognomonic for depleted iron stores.

Question 36Medical knowledge

Which laboratory finding is most characteristic of hereditary spherocytosis?

  1. Low serum haptoglobin with normal bilirubin
  2. Reduced red cell mass with normal reticulocytes
  3. Increased osmotic fragility of red cells Correct answer.
  4. Absence of spherocytes on peripheral smear

Explanation

Hereditary spherocytosis results from membrane protein defects that make red cells abnormally permeable and fragile, so osmotic fragility testing is classically increased. Chronic hemolysis also typically produces reticulocytosis and elevated indirect bilirubin.

Question 37Medical knowledge

A patient with sickle cell disease presents with acute chest syndrome. Which of the following is a recognized component of initial management?

  1. Routine corticosteroid therapy
  2. Incentive spirometry and empiric antibiotics Correct answer.
  3. Restriction of intravenous fluids to minimal amounts
  4. Immediate exchange transfusion for all patients

Explanation

Acute chest syndrome management includes respiratory support with incentive spirometry, empiric antibiotics, analgesia, and transfusion for significant hypoxia or worsening disease. Overhydration risks pulmonary edema, while exchange transfusion is reserved for severe or refractory cases.

Question 38Medical knowledge

A 62-year-old man has a hemoglobin of 9.1 g/dL, MCV 112 fL, and a serum B12 of 90 pg/mL. Which finding would most support a diagnosis of pernicious anemia over dietary B12 deficiency?

  1. Presence of hypersegmented neutrophils
  2. Elevated lactate dehydrogenase
  3. Low serum methylmalonic acid
  4. Positive intrinsic factor antibody Correct answer.

Explanation

Pernicious anemia is an autoimmune disorder marked by antibodies to intrinsic factor or gastric parietal cells, which supports the diagnosis over poor dietary intake. Methylmalonic acid is elevated in any B12 deficiency, so it does not distinguish the cause.

Question 39Medical knowledge

Which of the following is the most common inherited bleeding disorder?

  1. von Willebrand disease Correct answer.
  2. Hemophilia A
  3. Glanzmann thrombasthenia
  4. Hemophilia B

Explanation

von Willebrand disease is the most prevalent inherited bleeding disorder, affecting up to roughly 1% of the population in some estimates. Hemophilias A and B are X-linked and considerably rarer.

Question 40Medical knowledge

A patient with suspected heparin-induced thrombocytopenia has a 4T score of 6. Which of the following is the most appropriate immediate action?

  1. Start warfarin alone at a standard dose
  2. Transfuse platelets to maintain a count above 50,000
  3. Continue heparin and monitor platelet counts
  4. Stop heparin and start a non-heparin anticoagulant Correct answer.

Explanation

A high 4T score suggests heparin-induced thrombocytopenia, a prothrombotic disorder, so heparin must be stopped and a non-heparin anticoagulant such as argatroban started promptly. Warfarin should not be started alone because it can worsen thrombosis before the platelet count recovers.

Question 41Medical knowledge

Which coagulation abnormality is most typical of advanced liver disease?

  1. Elevated factor VIII level with shortened aPTT only
  2. Isolated prolongation of the bleeding time
  3. Prolonged prothrombin time with reduced factor VII Correct answer.
  4. Normal PT and aPTT with low platelets

Explanation

The liver synthesizes vitamin K-dependent factors including factor VII, so synthetic dysfunction prolongs the PT early and often the aPTT as well. Factor VIII is also produced by endothelium and tends to be elevated, not reduced, in liver disease.

Question 42Medical knowledge

A 34-year-old woman has a platelet count of 22,000/µL, petechiae, and no other cytopenias. Which finding would most favor immune thrombocytopenia (ITP) over a marrow production problem?

  1. Presence of ring sideroblasts
  2. Reticulin fibrosis on bone marrow biopsy
  3. Increased megakaryocytes on bone marrow biopsy Correct answer.
  4. Hypocellular marrow with fat replacement

Explanation

ITP is a destructive thrombocytopenia, so the marrow shows increased megakaryocytes compensating for peripheral platelet loss. Reduced or absent megakaryocytes would instead point to a production disorder such as aplastic anemia.

Question 43Medical knowledge

Which of the following is a major criterion for the diagnosis of antiphospholipid syndrome?

  1. A single low-titer antinuclear antibody
  2. Family history of venous thromboembolism
  3. Elevated D-dimer without thrombosis
  4. Persistent anticardiolipin antibodies on two occasions 12 weeks apart Correct answer.

Explanation

Antiphospholipid syndrome requires a clinical event (thrombosis or pregnancy morbidity) plus persistent antiphospholipid antibodies, confirmed on repeat testing at least 12 weeks apart. Single or transient antibody results are insufficient because they can occur with infection or drugs.

Question 44Medical knowledge

A patient with chronic myeloid leukemia has a marked leukocytosis with the Philadelphia chromosome. Which molecular abnormality underlies this disease?

  1. TET2 loss-of-function mutation
  2. BCR-ABL1 fusion tyrosine kinase Correct answer.
  3. JAK2 V617F mutation
  4. PML-RARA fusion

Explanation

Chronic myeloid leukemia is driven by the t(9;22) Philadelphia chromosome, which creates the BCR-ABL1 fusion tyrosine kinase targeted by imatinib. JAK2 V617F characterizes myeloproliferative neoplasms such as polycythemia vera, and PML-RARA defines acute promyelocytic leukemia.

Question 45Medical knowledge

A patient with polycythemia vera has a hematocrit of 58%. Which of the following is the most appropriate initial therapy in addition to phlebotomy?

  1. Low-dose aspirin Correct answer.
  2. Therapeutic anticoagulation with warfarin
  3. Routine erythropoietin administration
  4. Hydroxyurea for all patients regardless of risk

Explanation

Low-dose aspirin reduces thrombotic risk in polycythemia vera and is recommended in most patients without contraindications, along with phlebotomy to keep the hematocrit below 45%. Cytoreductive therapy is reserved for high-risk features such as prior thrombosis or advanced age.

Question 46Medical knowledge

Which finding is most characteristic of primary myelofibrosis?

  1. Isolated thrombocytosis with normal marrow
  2. Leukoerythroblastic smear with teardrop cells Correct answer.
  3. Bone marrow with increased blasts over 20%
  4. Marked erythrocytosis with low erythropoietin

Explanation

Primary myelofibrosis causes marrow fibrosis with extramedullary hematopoiesis, producing a leukoerythroblastic smear with nucleated red cells, immature granulocytes, and teardrop forms. Marrow fibrosis also leads to progressive cytopenias and massive splenomegaly.

Question 47Medical knowledge

A 55-year-old man has fatigue, splenomegaly, and a WBC of 120,000/µL with a left shift but fewer than 5% blasts. Which diagnosis is most likely?

  1. Hairy cell leukemia
  2. Acute myeloid leukemia
  3. Chronic lymphocytic leukemia
  4. Chronic myeloid leukemia Correct answer.

Explanation

Marked granulocytic leukocytosis with a left shift, splenomegaly, and few blasts is the classic chronic-phase presentation of chronic myeloid leukemia. Confirmation rests on detecting BCR-ABL1.

Question 48Medical knowledge

Which immunophenotype is characteristic of chronic lymphocytic leukemia?

  1. CD5-positive, CD23-positive B cells Correct answer.
  2. CD30-positive anaplastic large cells
  3. CD34-positive myeloblasts with myeloperoxidase
  4. CD10-positive, terminal deoxynucleotidyl transferase-positive blasts

Explanation

Chronic lymphocytic leukemia is a neoplasm of mature B cells that coexpress CD5 and CD23, which helps distinguish it from other small B-cell lymphomas. TdT and CD34 mark immature blasts, and CD10 suggests follicular lymphoma or acute lymphoblastic leukemia.

Question 49Medical knowledge

A patient with acute promyelocytic leukemia has DIC and a prolonged PT. Which treatment should be initiated immediately along with supportive care?

  1. All-trans retinoic acid Correct answer.
  2. Imatinib
  3. Rituximab
  4. Fludarabine

Explanation

Acute promyelocytic leukemia is driven by PML-RARA, and all-trans retinoic acid rapidly promotes differentiation and reduces the coagulopathy. Treatment is started as soon as the diagnosis is suspected rather than delayed for confirmation.

Question 50Medical knowledge

Which cytogenetic abnormality confers a favorable prognosis in acute myeloid leukemia?

  1. t(15;17) Correct answer.
  2. Monosomy 7
  3. Complex karyotype with five or more abnormalities
  4. t(6;9)

Explanation

The t(15;17) translocation defines acute promyelocytic leukemia, which is highly curable with targeted therapy and carries a favorable risk classification. Monosomy 7, complex karyotype, and t(6;9) are all adverse-risk features.