[Ultrastructural studies of the plasma cells in multiple myeloma].

Electron microscopic investigations of 38 patients with multiple plasmocytoma were carried out, the patients being divided into three groups according to the type of monoclonic immunoglobin in serum or urine. Light to moderate cellular-cytoplasmatic asynchronism was found as well as hypertrophic nucleoli and versatile changes in cytoplasmatic organelles of the poliferous plasmocytes. Cellular-cytoplasmatic asynchronism is discussed as a characteristic sign of neoplastic plasmatic cells. No correlation was found between the morphological changes in the nuclei and cytoplasma and the immunoglobin class, secreted from the cells.