case_images: PMC11822340_01
case_images: Peripheral smear showing marked rouleaux formation. Bone marrow aspirate showing neoplastic plasma cell with numerous azurophilic granules in cytoplasm.
case_images: bs9-7-e00218-g001.jpg
case_images: PMC11822340_01_bs9-7-e00218-g001.jpg
case_images: F1
case_images: The bone marrow aspirate and biopsy showed hypercellularity for age composed of reduced trilineage maturing hematopoiesis with replacement of marrow by sheets of plasma cells showing eccentrically placed nucleus with numerous ovoid-shaped intracytoplasmic coarse azurophilic granules mimicking mast cells (Fig. 1).
case_images: Flow cytometry plots showing kappa restriction of plasma cells.
case_images: bs9-7-e00218-g002.jpg
case_images: PMC11822340_01_bs9-7-e00218-g002.jpg
case_images: F2
case_images: Ig kappa restriction (Fig. 2). Immunohistochemistry performed on bone marrow biopsy showed strong positivity for CD138 and faint positivity for MUM1 also revealing a plasma cell phenotype.