Pure erythroid leukemia

A 57-year-old man presented with hemoglobin, white blood cell, and platelet counts of 67 g/L, 3.9 × 10⁹/L, and 47 × 10⁹/L, respectively. Peripheral blood smear revealed proerythroblasts (panels A-C; Wright-Giemsa stain; 100× objective, original magnification ×1000). Bone marrow aspirates showed hypercellularity, 80% to 90% of the cells being erythroid progenitors with remarkable dyspoietic features, with 30% to 40% proerythroblasts having large irregular nuclei, dispersed chromatin, 1 to 3 nucleoli, deeply basophilic cytoplasm, and high nuclear-to-cytoplasmic ratios (panels D-J; Wright-Giemsa stain; 100× objective, original magnification ×1000 [D-I] and 40× objective, original magnification ×400 [J]). Bone marrow biopsy showed high proportion of blast-like cells without expressing CD20, CD3, terminal deoxynucleotidyl transferase, myeloperoxidase, factor VIII, CD34, or glycophorin A. Flow cytometry revealed cell clone positivity for CD117, CD71, and CD36. Cytogenetics showed complex karyotype with loss of TP53 [del(5q−), del(7−), del(17p−), and gain(19+)].

Pure erythroid leukemia represents <1% of the cases of acute myeloid leukemia and evolves from a prior myelodysplastic syndrome or develops de novo. It presents a dismal prognosis, with no standardized therapy. Erythroid markers such as hemoglobin, glycophorin, spectrin, CD36, CD71, and ferritin and other molecules related to cell membrane structure are often employed in immunohistochemistry or flow cytometry to detect leukemia cells, depending on the maturation stage of the erythroid precursors.