title: Malignant lymphoma of the thyroid gland with plasma cell differentiation (plasmacytoma).
abstract: An unusual case of malignant lymphoma of the thyroid is reported. The predominant appearance of the neoplasm was that of a large cell ("histiocytic") lymphoma, but a discrete portion of the tumor showed features typical of plasmacytoma. Electron microscopy revealed a wide spectrum of cell types, ranging from very immature lymphoid cells to relatively well-developed plasma cells. The findings support the concept that the neoplastic process represents an immunoblastic sarcoma composed of proliferating transformed B lymphocytes (immunoblasts) and their progeny (plasma cells) rather than two distinct lymphoid neoplasms occurring simultaneously.
mesh_terms: D000368:Aged; D006801:Humans; D008223:Lymphoma / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D010954:Plasmacytoma / Q000648:ultrastructure*; D013964:Thyroid Neoplasms / Q000648:ultrastructure*