Figure 1. Morphological features of plasma cell leukemia. (A) The peripheral blood film shows lymphoplasmacytic cells and background rouleaux. (Wrights-Giemsa stain at 60× magnification). (B) The bone marrow aspiration is markedly hypercellular with increase in plasma cells. (May-Grunwald Giemsa stain at 20× magnification). (C, D) The trephine biopsy showed suppression of trilineage hematopoiesis and infiltration by neoplastic plasma cells, which have eccentric nucleus, chromatin arranged in a cog-wheel pattern and abundant basophilic-to-pinkish cytoplasm. (H&E stain at 20× and 60× magnification). (E) The neoplastic plasma cells are CD138-positive. (F) CD117-negative. (G) Lambda-light-chain-restricted. (H) Kappa light chain-negative. (I) Cyclin D1-positive. (J) CD56-negative. (Immunohistochemistry stain at 4× magnification)