[Clinical features and prognosis of rare subtypes of renal cell carcinoma]

Objective: To investigate the clinical features and prognosis of rare subtypes of renal cell carcinoma. Methods: This retrospective study collected the data of 52 rare subtypes of renal cell carcinoma of patients who underwent surgery from January 2002 to December 2014 at Department of Urology, Peking University First Hospital. There were 12 patients with collecting duct carcinoma, 5 patients with Xp11.2 translocation renal cell carcinoma, 5 patients with mucinous tubular and spindle cell carcinoma, 30 patients with unclassified renal cell carcinoma. The study group included 25 male and 27 female patients, with mean age of 52 years. The mean tumour size was (6.5±3.9) cm (range: 1.5 to 21.0 cm). The basic clinical features, gross appearance, Fuhrman nuclear grade, TNM staging and prognosis of rare subtypes of RCC were studied. The OS curves were obtained for rare subtypes of renal cell carcinoma using the Kaplan-Meier method and compared using a Log-rank test. Results: The rate of lymph node and distant metastasis were 34.6% (18/52) and 17.3% (9/52). Malignancies were screened and detected by color Doppler ultrasonography or CT scan, however, no case was diagnosed before operation or aspiration, all cases were confirmed by the pathological examination. The average period of postoperative follow-up process was 65 months, and the mean survival time was (34±23) months. Conclusion: The clinical features of rare subtypes of renal cell carcinoma are similar to those of clear cell renal cell carcinoma, while the imaging changes will be helpful for diagnosis before operation.