A) Bone marrow aspirate demonstrating megakaryoblast clumping and abundant cytoplasm with budding projections. Wright-Giemsa stain, 100x magnification. Courtesy of Dr. Donald Mahoney. B) Bone marrow biopsy demonstrating clusters of megakaryoblasts, atypical megakaryocytes, megakaryocytic differentiation, and fibrosis. H&E stain, 400x magnification. Courtesy of Dr. Andrea Sheehan.