RESUMO
OBJECTIVES: To analyze the main epidemiological, clinical and pathological features of cystic renal carcinoma in comparison with those of solid tumors. To determine the reliability of the preoperative diagnostic methods to distinguish these cysts from other cystic renal disease. METHODS: The study comprised 286 carcinomas that had been treated over a period of 25 years. These cases were divided into two groups; 268 solid tumors and 18 cystic lesions. We analyzed patient age at onset, sex, tumor location and intrarenal status, clinical features, tumor size, cellular type, grade, stage and survival rate. In the group with cystic lesions, we analyzed the diagnostic methods used and the diagnosis made preoperatively. RESULTS: 6.29% were cystic carcinomas. There were no differences between the solid and cystic lesions except for the slightly larger size of the latter (9.88 cm versus 8.01 cm). No significant differences were found for survival. The IVP and arteriograms only disclosed an expansive renal process suggestive of a neoplasm in 9 and 3 cases, respectively. Ten cases were evaluated by US and 13 by CT, which revealed a complicated cystic lesion. The fine needle punction aspiration biopsy, which was done in 3 cases, was negative. On the basis of the findings, a diagnosis of cystic carcinoma was made in 11 cases and multilocular cystic nephroma in 3 cases. The older cases that had been seen when US or CT were unavailable had been diagnosed as having renal carcinoma. CONCLUSIONS: Similar results, with special reference to the high rate of false negatives of the cytological study, have been reported in the literature.
