A patient presents with anemia characterized by a marked reduction in the number of reticulocytes, normal white blood cell and platelet counts, and a bone marrow biopsy showing a hypoplastic marrow. What is the most likely diagnosis?

A Aplastic anemia ✓
B Myelodysplastic syndrome
C Pure red cell aplasia
D Paroxysmal nocturnal hemoglobinuria

Explanation

Aplastic anemia is characterized by a failure of the bone marrow to produce blood cells, resulting in pancytopenia (although in this case, only anemia is mentioned) and a hypoplastic marrow on biopsy. The reduction in reticulocytes indicates inadequate erythropoiesis.

Source

Harrison's Principles of Internal Medicine
Hematology Hematology: Anemia Hematology: Anemia Medium MEDICAL Confidence: high