Histopathological study of bone marrow biopsy specimens. A. Immunohistochemical study revealed CD138 expression in plasmocytes (in brown). B. Bone marrow biopsy with an estimated cellularity of 50%. There was evidence of trilinear hematopoiesis. Megakaryocytes showed multiple lobules in their nuclei and exhibited increased number, varied sizes, and were slightly dysmorphic. Stromal degeneration, along with histiocytes with hemosiderin deposits and thrombocytosis were also visible. Approximately 10% of the cells were plasmocytes.