Inflammatory pseudotumor of the kidney

Abstract

A 38-year-old man without prior contributory history presented complaining of a tumor in the left upper abdomen without tenderness. Suspecting renal cell carcinoma of the dark cell type, a nephrectomy was performed. Microscopic examination showed a proliferation of spindle cells containing numerous blood vessels. A diffuse infiltrate of lymphocytes and plasma cells was scattered throughout the lesion.