EXPLOSIVE METASTASIS OF A CARCINOMA OF TH E RENAL PELVIS IN ANALGESICKIDNEY

A 48-year-old male experienced sudden pain in the right flank and macr ohematuria with subsequent repeated episodes of painless macrohematuri a. In the radiological work-up, CT was interpreted as inflammatory enl argement of the right kidney and MRI diagnosed renal vein thrombosis. There was some suspicion that there might be a malignancy. Five months later the patient had to be admitted to the hospital, because of incr easing flank pain, desiccation and general signs of inflammatory disea se. Radiological changes compatible with pulmonary metastases were fou nd. Biopsy of enlarged mediastinal lymph nodes revealed undifferentiat ed carcinoma. Because of the expression of Cytokeratin primary urothel ial carcinoma was suspected. The patient then deteriorated rapidly. No further specific therapy could be carried out. Death was chiefly caus ed by respiratory insufficiency 5 months after the first episode of pa in and 1 month after admission. Autopsy revealed a poorly differen- ti ated urothelial carcinoma of the right renal pelvis, with extensive ca rcinomatous angiomatosis and metastases to the left kidney, lungs, and regional and mediastinal lymph nodes. Independently of the carcinoma, both kidneys also showed interstitial nephritis, papillary necrosis a nd capillarosclerosis, compatible with analgesic-user kidney (''phenac etin kidney'') in the absence of a corresponding history.