Cystic Renal Cell Carcinoma

Purpose To evaluate clinicopathologic features and survival outcomes of unilocular cystic renal cell carcinoma (cRCC) compared with purely solid renal cell carcinoma (RCC), and to evaluate the oncologic aggressiveness of unilocular cRCC. Methods The relevant data of 957 patients with sporadic unilateral RCCs underwent surgical treatment in 2 institutions from Jan 2014 to Oct 2018 were obtained. We excluded multilocular cystic renal neoplasm of low malignant potential (MCRNLMP), RCCs with multilocular cysts and necrotic RCCs. 74 unilocular cRCCs were identified by pathology reports. We performed propensity score matching (PSM) and randomly selected 148 purely solid RCCs. The clinicopathologic features and survival outcomes were compared properly. Results After PSM, age, BMI, Charlson Comorbidity Index, and postoperative Chronic Kidney Disease grade were not significantly different. Both overall survival and cancer-specific survival of unilocular cRCCs were significantly better than the purely solid RCCs by the log-rank test. Twenty-five cases of solid RCCs were in the pT3 or pT4 stage, while no pT3 or pT4 tumors were found in unilocular cRCCs. Fuhrman grade, pT stage, lymphatic metastasis and tumor diameter were found to be independent prognostic factors. Conclusion Unilocular cRCCs have a lower Fuhrman grade and pathological stage and a better prognosis compared with solid RCC. Unilocular cRCCs still probably have lymphatic metastasis at diagnosis and may have postoperative metastasis, which is different from MCRNLMP. We recommend that the diagnosis of unilocular cRCC should be reflected in pathology reports. Different subtypes of cRCC should be taken into consideration in counseling and management.

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“…In some studies, it was there were many papillary RCCs in unilocular cRCCs [1,22]. This is consistent with our ndings.…”

Section: Discussionsupporting

confidence: 93%