Invasion of nonhematopoietic tissues with megakaryocytes in an animal that died of advanced BCR/ABL disease. (A,B) FACS analysis of cells that were isolated from the ascitic fluid stained for the megakaryocyte- and platelet-specific marker CD41 and for the myeloid markers Gr-1 and Mac-1. (C) Histology of the ascitic cells stained with Wright Giemsa demonstrates cells at various stages of maturation. (D) Megakaryocytes (arrow) were identified in cytospin preparations of liver cells. The liver was massively enlarged and invaded by malignant hematopoietic cells (E) that destroyed the architecture of the organ. (F) The liver at higher magnification is shown. Original magnification of panels C-F, × 60. Percentages in A and B indicate percent positive for the respective markers.