USMLE_STEP_3_2026_COMPREHENSIVE_SET_SOLVED_QUESTIONS_AND_SOLUTIONS

USMLE STEP 3 2026 COMPREHENSIVE SET
SOLVED QUESTIONS AND SOLUTIONS



◉Myelofibrosis. Answer: Obliteration of the bone marrow with
fibrosis
Megakaryocytes produce PDGF → fibrosis


Presentation:
1. Splenomegaly
2. Teardrop RBCs


Lab findings
↓ RBCs
variable WBCs
variable platelets
30-50% JAK2 mutation


◉Teardrop RBCs are associated with which disease?. Answer:
myelofibrosis

,◉Myelodysplastic syndrome. Answer: Stem cell disorder involved in
ineffective hematopoiesis resulting in defects in cell maturation of
nonlymphoid lineages


Lab Findings:
Hypercellular bone marrow
Peripheral cytopenia
Pseudo-Pelger-Huet Anomaly- neutrophils with bilobed nuclei


Causes:
De novo mutations
Radiation
Benzene exposure
Chemotherapy


↑ Risk of transformation to AML


◉Pseudo-Pelger-Heut Anomaly is associated with which disease?.
Answer: Myelodysplastic syndromes


Neutrophils with bilobed nuclei (heut duet)

, ◉Aplastic Anemia. Answer: Caused by failure or destruction of
myeloid stem cells 2/2:
- Radiation
- Drugs: benzene, chloramphenicol, alkylating agents,
antimetabolites
- Viruses: EBV, HIV, Hepatitis
- Fanconi anemia
- Idiopathic


Lab findings:
↓ Reticulocyte count
↑ EPO
Pancytopenia
Hypocellular bone marrow


Treatment:
Immunosuppression- anti-thymocyte globulin, cyclosporine
Bone marrow allograft
Transfusion
Bone marrow stimulation with GM-CSF