Sarcomatoid chromophobe renal cell carcinoma revealed by acute pyelonephritis in a diabetic patient.

Chromophobe renal cell carcinoma (CRCC) is a rare tumor comprising 2 types of cells (eosinophilic and clear cells), coexisting in varying proportions. CRCC has an overall good prognosis. However, the rarely encountered sarcomatoid differentiation is associated with a pejorative outcome and must, therefore, be rigorously ruled out. Acute pyelonephritis and other infectious complications rarely occur. We report a case of CRCC with sarcomatoid differentiation in a woman in her sixties which was revealed by acute pyelonephritis and had a lethal outcome.