MD Hematology and Oncology 2

Question 1

A 45-year-old presents with fatigue, splenomegaly, and a WBC of 120,000/μL with a left shift. Cytogenetics reveals t(9;22). Which kinase is constitutively activated in this condition?

Accepted Answer

BCR-ABL1

Answer

The Philadelphia chromosome t(9;22) creates the BCR-ABL1 fusion gene, producing a constitutively active tyrosine kinase that drives CML.

Question 2

A 70-year-old man has a hemoglobin of 8 g/dL, serum ferritin of 800 ng/mL, low TIBC, and elevated ESR. His anemia is most consistent with:

Accepted Answer

Anemia of chronic disease

Answer

Anemia of chronic disease features low iron, low TIBC, high ferritin (iron trapped in stores), and normal-to-low reticulocytes due to hepcidin-mediated sequestration.

Question 3

A patient on warfarin presents with a PT of 45 seconds and an INR of 4.2, but is not bleeding. The most appropriate next step is:

Accepted Answer

Hold warfarin and monitor closely

Answer

For supratherapeutic INR (4.1–10) without bleeding, simply holding warfarin and monitoring is recommended; IV vitamin K is reserved for bleeding or INR >10.

Question 4

Which cytokine is primarily responsible for the thrombocytosis seen in reactive (secondary) thrombocytosis following iron deficiency?

Accepted Answer

Thrombopoietin

Answer

Thrombopoietin (TPO) levels rise in iron deficiency due to increased erythropoietic drive and cross-stimulation of megakaryocytes, causing reactive thrombocytosis.

Question 5

A 30-year-old woman has episodic hemolysis, pancytopenia, and venous thrombosis. Flow cytometry shows absence of CD55 and CD59 on RBCs. What is the defect?

Accepted Answer

GPI anchor deficiency

Answer

Paroxysmal nocturnal hemoglobinuria (PNH) results from a PIGA mutation causing GPI anchor deficiency, rendering cells vulnerable to complement-mediated lysis.

MD - Doctor of Medicine Practice Test

MD - Doctor of Medicine Practice Test

MD Hematology and Oncology 2