Diagnosis and treatment of multilocular cystic renal cell carcinoma

Background and purpose:WHO defined multilocular cystic renal cell carcinoma(MCRCC) as an absolute renal carcinoma in 2004.It is a rare kind of tumor;therefore there is a few articles about this disease.Our study was aimed to explore and improve the diagnosis and treatment of MCRCC.Methods:The data of 5 cases(3 males and 2 females) MCRCC classified according to 2004 WHO criteria were reviewed retrospectively.The tumor was incidentally found in 4 out of 5 cases.Renal ultrasound and CT scans showed a well-defined cystic mass with irregular thickening wall or septa in 5 cases without visible nodules found.For treatment,open radical or partial nephrectomy was done in those cases.Results:Postoperative pathological findings confirmed the diagnosis.The mean diameter of the tumors was 5.5 cm.Microscopically,the wall and septa lined by one or several layers of clear was observed in all cases.The clear cells formed small collections but did not form expansive nodules.The TNM stage of all 5 cases was T1N0M0.For pathologic grade,4 cases were G1 and 1 case was G2.The follow-up was 20 months,local recurrence or distant metastasis was not found.Conclusion:MCRCC is an uncommon subtype of RCC,it was a lower malignant potential and a better prognosis compared with other types of RCC according to the literature.The preoperative diagnosis of MCRCC immediately depends on imaging studies.Surgery may be an appropriate treatment option for MCRCC.