Small renal adenocarcinoma with metastases.

A case of a 9 mm. renal adenocarcinoma with widespread metastases, including multiple osteoblastic metastases, is presented. An extensive clinical investigation to identify a primary lesion in this patient was negative, including prostatic biopsy, serum electrophoresis, bone marrow biopsy, excretory urography, renal arteriography and abdominal computerized axial tomography scan. Examination at autopsy documented a small adenocarcinoma of the right kidney with local capsular invasion and metastases to the lungs, para-aortic lymph nodes and vertebrae. The differential pathologic and clincal features separating renal adenoma from adenocarcinoma are discussed.