Overview, Bone Marrow Failure Syndromes, and Pure Red Cell Aplasia

Question · easy

A 24-year-old man presents with 2 weeks of easy bruising; he has petechiae and pallor but no lymphadenopathy or splenomegaly. CBC shows hemoglobin 6.8 g/dL, WBC 1,400/μL (ANC 350/μL), platelets 12,000/μL, and an absolute reticulocyte count of 30,000/μL. Bone marrow biopsy is 10% cellular, mostly fat. Which set of findings classifies his aplastic anemia as severe?

Pancytopenia with a hypercellular marrow and megakaryocyte hyperplasia Hypocellular marrow plus ANC <500/μL, platelets <20,000/μL, and absolute reticulocytes <60,000/μL ANC <1000/μL with splenomegaly and nucleated red cells on smear Hypocellular marrow with isolated anemia and a corrected reticulocyte count of 3%

Question · medium

A 62-year-old woman is newly diagnosed with severe aplastic anemia (ANC 300/μL, platelets 15,000/μL, 15% cellular marrow). HLA typing of her only sibling shows a mismatch, and no matched unrelated donor is readily available. What is the most appropriate first-line therapy?

Erythropoietin and G-CSF monotherapy Rabbit antithymocyte globulin plus cyclosporine Horse antithymocyte globulin plus cyclosporine, prednisone, and eltrombopag Matched-sibling allogeneic hematopoietic stem cell transplantation

Question · medium

A 30-year-old woman with newly diagnosed severe aplastic anemia undergoes flow cytometry, which detects a small PNH clone (CD55/CD59-deficient granulocytes, 18%). She has no hemolysis, hemoglobinuria, or thrombosis. Which statement about the PNH clone is most accurate?

It supports an immune pathophysiology and predicts responsiveness to immunosuppressive therapy It indicates she should immediately receive eculizumab regardless of hemolysis It mandates urgent splenectomy to prevent clone expansion It confirms the diagnosis of hypoplastic myelodysplastic syndrome

Question · hard

A 45-year-old man with common variable immunodeficiency develops progressive normocytic anemia (hemoglobin 7.2 g/dL) with a reticulocyte count of 0.2% over 8 weeks. WBC and platelet counts are normal. Bone marrow biopsy shows giant pronormoblasts with markedly decreased erythroid precursors and preserved myeloid and megakaryocytic lineages. Parvovirus B19 IgM and IgG are negative. What is the most appropriate next diagnostic test and treatment?

Bone marrow cytogenetics; horse ATG plus cyclosporine Repeat serology in 4 weeks; observation with transfusion support only Parvovirus B19 DNA PCR; intravenous immune globulin Chest CT for thymoma; surgical thymectomy

Question · easy

A 58-year-old man is found to have an isolated anemia (hemoglobin 8.4 g/dL) with reticulocytopenia and normal WBC and platelet counts. Bone marrow biopsy confirms pure red cell aplasia. In addition to reviewing his medications, which evaluation is indicated in every patient with acquired PRCA?

Chromosome breakage studies with diepoxybutane Red cell transfusion followed by repeat biopsy in 3 months Mediastinal imaging to exclude thymoma Serum erythropoietin level measurement