Severe glomerular mesangiolysis in a patient with rectal adenocarcinoma treated with cytotoxic drugs.

A 72 year old man with rectal adenocarcinoma developed chronic renal failure when treated by surgery and subsequent chemotherapy (5-fluorouracil, Mitomycin C and Cytosine arabinoside) and immunotherapy. Light microscopy provided evidence of severe glomerular changes with extensive mesangiolysis and vascular damage. Electron microscopy confirmed the mesangiolysis and showed nuclear changes in mesangial cells with nuclear pockets, chromatin loss and margination. There was further indirect evidence of endothelial cell damage. It is suggested that the glomerular changes should be attributed to a direct cytotoxic effect on the mesangial cells.