Coexistence of Cyst and Tumor in the Same Kidney

Abstract

Five cases of coexistent renal cyst and neoplasm are reported, including renal cyst plus clear-cell carcinoma of the kidney in 4 patients and renal cyst plus Wilms's tumor in the fifth patient. Two patients with clear-cell carcinoma and renal cysts also had widely separated benign adenomas. Cyst puncture, aspiration, and histopathological assay of the aspirant facilitate cytological diagnosis of malignant neoplasm in a renal cyst. Histochemical identification of aspirated tumor breakdown products also indicates the presence of a neoplasm. The double-contrast cyst study and selective renal arteriography or nephrotomography define the lesion anatomically, sometimes showing abnormal vessels indicative of malignant neoplasm.