Histopathological Features of Plasma Cell Dyscrasia with Polyneuropathy and Endocrine Disturbances, with Special Reference to Germinal Center Lesions

The biopsy and autopsy materials of 41 cases showing clinicalmanifestations consistent with those of plasma cell dyscrasiawith polyneuropathy and endocrine disturbances were studiedby light microscopy and immunohistochemistry. The results obtainedare as follows: 1) Lymph node swelling was generalized and thesize of the nodes varies up to that of a thumb tip. 2) Angiosclerosisin the germinal centers of swollen lymph nodes is one pathognomonicfeature in this disorder and was common to all the cases examinedand occurred in the early stage. 3) The other feature is monoclonalproliferation of plasma cells (plasmacytoma) occurring not onlyin the bone marrow (five biopsy cases, seven autopsy cases)but also in the lymph nodes (nine biopsy cases, four autopsycases). 4) If all the bone lesions detected roentgenologicallyare regarded as being due to monoclonal proliferation of plasmacells, it was demonstrated in 26 of 31 biopsy cases (84%) andin 14 of 16 autopsy cases (88%). This suggests that the plasmocytomaparticipates in the development of clinical manifestations ofthe disorder. 5) Besides the characteristic lesions in the lymphnodes, proliferation of small blood vessels and hemangioma-likelesions were found in the spleen, subcutaneous connective tissueand visceral adipose tissues, and hemangiomatous verrucae werealso seen in the skin. As to the pathogenesis of the vascularlesions, vasculitis may be suggested. 6) The his-tologic featuresin the other organs and tissues seem to be closely related tothe development of varied clinical manifestations and are representedby atrophy in the sural nerves, gastrocnemius muscles, and endocrineor reproductive organs.