Focal segmental glomerulosclerosis in kidney resected for renal cell carcinoma

A diagnosis of renal dysfunction is usually made on the basis of clinical, biochemical, radiologic, and renal tissue analysis. Accurate diagnosis often requires a renal biopsy, but that procedure is contraindicated in certain clinical circumstances, particularly in patients who have only one kidney. We describe a patient who previously had undergone left nephrectomy for a renal clear cell carcinoma, in whom the diagnosis of focal segmental glomerulosclerosis was made on retrospective analysis of remnant renal tissue from the patient's nephrectomy specimen.