Solitary Cyst and Clear Cell Adenocarcinoma of the Kidney: Report of 2 Cases and Review of the Literature

Abstract

We report 2 cases of a solitary simple cyst of the kidney harboring clear cell adenocarcinoma in the wall of the cyst. Cysts of the kidney may be divided into solitary cysts, that is large, unilocular cysts with a thin wall, and multilocular cysts, that is sharply demarcated multilocular epitheliallined cysts with compression of the adjacent renal parenchyma. There are 4 types of tumor and cyst that occur in the same kidney, and our cases belonged to type 3.Suspicion of malignancy was raised by preoperative cytological examination of the fluid of the cysts. Perioperatively, however, no gross evidence of malignancy was found in either case. Frozen section biopsy in case 1 failed to confirm the diagnosis. The cysts were removed by partial nephrectomy. Patient 1 died within 2 years of widespread metastases. Patient 2 had undergone nephrectomy and was well. Based on the literature and our findings we strongly recommend the surgical approach of partial nephrectomy followed by total nephrectomy when the diagnosis has been confirmed.