MD Hematology and Oncology 4 — Questions and Answers
Question 1: A 35-year-old woman with sickle cell disease develops sudden chest pain, fever, hypoxia, and a new pulmonary infiltrate during a painful crisis. The most likely diagnosis is:
- Pulmonary embolism
- Acute chest syndrome (Correct answer)
- Lobar pneumonia
- Pulmonary hypertension
Correct answer: Acute chest syndrome
Acute chest syndrome (new pulmonary infiltrate + chest symptoms) is the leading cause of death in sickle cell disease and requires exchange transfusion in severe cases.
Question 2: Which gene mutation, found in >95% of polycythemia vera patients, is used as a diagnostic criterion?
- BCR-ABL1
- JAK2 V617F (Correct answer)
- CALR exon 9
- MPL W515
Correct answer: JAK2 V617F
JAK2 V617F is present in >95% of PV patients and causes constitutive JAK-STAT signaling, driving erythrocytosis independent of EPO.
Question 3: A 50-year-old man receiving cisplatin-based chemotherapy develops fatigue with hemoglobin 7.5 g/dL, low reticulocytes, and inappropriately low erythropoietin. The mechanism of his anemia is:
- Hemolysis
- Bone marrow suppression
- Renal EPO suppression from cisplatin nephrotoxicity (Correct answer)
- Iron deficiency from GI bleeding
Correct answer: Renal EPO suppression from cisplatin nephrotoxicity
Cisplatin causes nephrotoxicity that impairs renal EPO production, leading to anemia disproportionate to the degree of myelosuppression.
Question 4: A newborn develops jaundice within 24 hours of birth and hydrops fetalis. The Coombs test is positive. The mother is O-negative and the baby is O-positive. What is the mechanism?
- ABO incompatibility causing mild hemolysis
- Rh hemolytic disease of the newborn due to anti-D IgG (Correct answer)
- G6PD deficiency triggered by maternal medications
- Hereditary spherocytosis
Correct answer: Rh hemolytic disease of the newborn due to anti-D IgG
Rh incompatibility (Rh-negative mother sensitized to Rh-positive fetal cells) causes IgG anti-D to cross the placenta and destroy fetal RBCs, causing hemolytic disease of the newborn.
Question 5: A 65-year-old presents with back pain, a serum M-spike, and lytic bone lesions on X-ray. CRAB criteria are met. Which bisphosphonate reduces skeletal events in multiple myeloma?
- Alendronate
- Zoledronic acid (Correct answer)
- Pamidronate oral
- Etidronate
Correct answer: Zoledronic acid
Zoledronic acid (IV) is preferred over other bisphosphonates for multiple myeloma bone disease due to superior efficacy in reducing skeletal-related events.
Question 6: Which test is most sensitive for detecting early iron deficiency before anemia develops?
- Serum iron
- Hemoglobin
- MCV
- Serum ferritin (Correct answer)
Correct answer: Serum ferritin
Serum ferritin falls first in iron deficiency, reflecting depleted iron stores before iron-restricted erythropoiesis and anemia develop.
Question 7: A 28-year-old man with hemoglobin SS disease is started on hydroxyurea. Which mechanism accounts for its primary benefit in sickle cell disease?
- Inhibits sickling by chelating calcium
- Increases fetal hemoglobin (HbF) production (Correct answer)
- Reduces blood viscosity by decreasing platelet count
- Blocks sickling by oxidizing HbS
Correct answer: Increases fetal hemoglobin (HbF) production
Hydroxyurea induces HbF synthesis, which dilutes HbS within red cells and inhibits polymerization, reducing vaso-occlusive crises.
MD Hematology and Oncology 4
A 35-year-old woman with sickle cell disease develops sudden chest pain, fever, hypoxia, and a new pulmonary infiltrate during a painful crisis.
The most likely diagnosis is: