Peripheral Blood
Circulating blasts in the peripheral blood comprise 58% of leukocytes. The blasts are small, with smooth to slightly irregular nuclear contours and scant cytoplasm. No Auer rods are seen.
Bone Marrow Aspirate
Blasts comprise the majority of nucleated cells on the aspirate smear (90%). The blasts are negative for myeloperoxidase and NSE by cytochemical stains.
Flow cytometry
By flow cytometry, the blasts are positive for CD34, CD45 (dim), CD7, and HLA-DR. The blasts lack T, B, or myeloid lineage specific markers, including CD3 (surface or cytoplasmic), CD19, cytoplasmic CD79a, myeloperoxidase (MPO), CD117, CD13, CD61, and monocytic markers.
