[Type 3 membranoproliferative glomerulonephritis: an unusual variety of well-known pathology].

Light microscopy, immunohistochemistry, and submiscroscopy were used to study a renal biopsy specimen obtained from a 51-year-old old male suffering from type 3 membranoproliferative glomerulonephritis (MPGN-3) concurrent with HCV infection. Along with the signs characteristic of MPGN-3 (glomerulosclerosis; crescents; subendothelial and subepithelial deposits; proliferation of mesangial and endothelial cells), abundant pro- and myelocytes were found in the glomerular capillary lumens with active granular formation in the Golgi apparatus and with granular exocytosis into the glomerular basement membrane. Apoptotic elements were recorded among both glomerular and tubular epithelial cells.