April 2021 – Presented by Dr. Alexander Ladenheim (Mentored by Dr. Elham Vali Betts)

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Clinical History

A previously healthy 60-year-old male presents with fatigue and a complete blood count shows macrocytic anemia (Hgb 8.3, MCV 97), thrombocytopenia (platelets 106) and leukopenia with a differential remarkable for neutropenia and lymphopenia (WBC 2.3, absolute neutrophil count 0.8, absolute lymphocyte count 0.6) and a low reticulocyte index. The patient’s routine chemistries, vitamin B12, and folate levels are normal. A bone marrow biopsy is performed.

Microscopic Findings

Bone marrow biopsy shows a hypercellular marrow (approximately 70% cellularity) with intact trilineal hematopoiesis, mild reticulin fibrosis, and adequate iron stores. Blasts are not increased. The marrow aspirate shows numerous erythroid precursors and megakaryocytes with the findings seen below:

a H&E, core biopsy (100x)

b Giemsa, aspirate smear (500x)

c Prussian blue, aspirate smear (1000x)

d CD61, core biopsy (100x)