[Renal sinus lipomatosis, a pseudotumorous transformation]

A case of longstanding chronic pyelonephritis associated with severe recurrent nephrolithiasis followed by excessive lipomatosis, ureteritis cystica and xanthogranulomatous pyelonephritis is presented. In addition to the definition and morphologic description of lipomatosis its differential diagnosis is discussed. This also applies to the pathogenesis of these diseases. The special role of lipomatosis in the perpetuation of a circulus vitiosus is stressed. In special cases it seems to be justified to speak of clinical malignant lipomatosis.