Cystic renal cell carcinoma: a report on outcomes of surgery and active surveillance in patients retrospectively identified on pretreatment imaging

To evaluate the outcomes of surgical intervention and active surveillance in patients diagnosed with cystic renal cell carcinoma at our hypothesized radiologic cutoff of >50% cystic.

We identified all patients with a pathologically confirmed cystic renal mass that fit our criteria from 2000 to 2015 (n=430). Patients with lack of CT imaging, tumors <50% cystic on imaging, multifocal tumors and prior renal cell carcinoma were excluded (n=292). Patients were stratified into benign or malignant subgroups, and radiologic, clinicopathologic and oncologic features were obtained. Univariate and multivariate associations between clinicoradiologic parameters in each group were analyzed. A separate cohort of patients managed by active surveillance for cystic renal cell carcinoma was similarly reviewed.

Of the 138 cases of cystic renal cell carcinoma cases identified, 102 (73.9%) were renal cell carcinoma and 36 (26.1%) benign masses. Most tumors were Fuhrman grade 1-2 (77.5%), ≤pT2 stage (83.4%) and clear cell histology (65.9%). On univariate analysis, male gender, a solid component and increasing Bosniak classification were significant for malignancy. In a separate cohort, we identified 38 patients on active surveillance. Growth rate was found to be 1.0 mm/year overall and 2.3 mm/year for the solid component. After a median follow-up of >4 years for all cohorts, there was no evidence of recurrence or metastasis from cystic renal cell carcinoma.

Patients with unifocal cystic renal cell carcinoma evaluated using a standardized radiologic threshold of >50% cystic have an excellent prognosis on both active surveillance and following surgical resection.

The Journal of urology. 2018 Feb 26 [Epub ahead of print]

Mahyar Kashan, Mazyar Ghanaat, Andreas M Hötker, Cihan Duzgol, Alejandro Sanchez, Renzo G DiNatale, Kyle A Blum, Maria Becerra, Brandon J Manley, Jozefina Casuscelli, Michael Chiok, Jonathan A Coleman, Paul Russo, Satish K Tickoo, Oguz Akin, A Ari Hakimi

Department of Surgery-Urology Service., Department of Radiology., Department of Surgery-Urology Service; Department of Urology, Miller School of Medicine University of Miami, Miami, FL., Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Urology, Ludwig-Maximilians University, Munich, Germany., Department of Pathology., Department of Surgery-Urology Service. Electronic address: .