GLOMERULAR LESIONS IN MULTIPLE MYELOMA

Abstract

An autopsy case of multiple myeloma (IgG, .lambda. type), clinically characterized by decreased glomerular filtration rate, is reported with particular emphasis on changes in the glomeruli of kidneys. Histologically, the glomeruli revealed slight increase in mesangial matrix and focal thickening of tuft capillary wall. By EM, deposits were observed in a subendothelial location in the glomerular capillary walls, and inclusions were noted in the cytoplasm of the visceral epithelial cells. Histoimmunofluorescent study of the kidney demonstrated intense focal and slight diffuse positivity against labeled antisera of anti-IgG and anti-.lambda. type of L chain on the capillary wall of the glomerular tufts. Other immunoglobulins were not demonstrable in capillary walls. These findings represent the intraglomerular deposition of paraprotein of multiple myeloma without amyloidosis.