Ultrastructure of a Human Malignant IgA-Producing Plasmacytoma
Document Type
Article
Publication Date
1-1-1975
Description
A rare kind of malignant, IgA-producing plasmacytoma was examined by light and electron microscopy. The plasmacytoma consisted of alternating clusters of two main types of cells: (1) light, rounded cells resembling immature plasma cells with vesicular nuclei, prominent nucleoli, and fairly well developed cytoplasmic organelles; and (2) darker, more differentiated and pleomorphic plasma cells in varying stages of development. The lighter cells were observed to undergo mitosis and probably gave rise to the darker cells through progressive differentiation. Both types of cells possessed some of the abnormalities observed by other investigators in plasma cells from patients with multiple myeloma and other malignant monoclonal gammopathies, including a tendency for nuclear maturation to lag behind cytoplasmic differentiation. Small membrane-enclosed intranuclear inclusions were observed occasionally in the lighter cells. Other cells observed in the plasmacytoma included bizarre "giant" cells, immature cells resembling plasmablasts, and macrophages. In addition, the plasmacytoma contained rounded extracellular deposits of a moderately electron-dense material which lacked fibrillar or crystalline organization. The material was osmiophilic, Sudan black B-positive, and moderately well stained with toluidine blue, but it failed to stain by the PAS procedure or with eosin.
Citation Information
Curtis, Sherill K.; Propp, Richard; Cowden, Ronald R.; and Tartaglia, A. P.. 1975. Ultrastructure of a Human Malignant IgA-Producing Plasmacytoma. Experimental and Molecular Pathology. Vol.22(3). 386-399. https://doi.org/10.1016/0014-4800(75)90083-0 PMID: 165096 ISSN: 0014-4800