Histologic sections of the breast show an extensive infiltration of immature cells with fine chromatin, distinct nucleoli and moderate amount of cytoplasm (H&E, 400x).
Immunohistochemical stain shows that the neoplastic cells are strongly positive for CD43 (400x).
Immunohistochemical stain shows that the neoplastic cells are positive for CD68 (400x).
Immunohistochemical stain shows that the neoplastic cells are positive for myeloperoxidase (400x).
The bone marrow biopsy shows normocellular (30-40%) bone morrow with increased immature cells (H&E, 400x).
The aspirate smear shows increased blasts. Some blasts have monocytic differentiation (Wright-Giemsa, 1000x).