Progression rate in Bosniak category IIF complex renal cysts

• Published in: Radiologia brasileira 2019-05, Vol.52 (3), p.155-160
• Main Authors: Tames, Amanda de Vasconcelos Chambi, Fonseca, Eduardo Kaiser Ururahy Nunes, Yamauchi, Fernando Ide, Arrais, Gabriela Maia Soares Messaggi, de Andrade, Thais Caldara Mussi, Baroni, Ronaldo Hueb
• Format: Article
• Language: English
• Subjects: Original; RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING
• ISSN: 0100-3984; 1678-7099; 1678-7099
• DOI: 10.1590/0100-3984.2018.0038

To evaluate progression rate of Bosniak category IIF complex renal cysts and the malignancy rate among surgically resected cysts. We performed a database search for complex renal cysts classified as Bosniak category IIF on computed tomography or magnetic resonance imaging between January 2008 and April 2016. Follow-up examinations (computed tomography or magnetic resonance imaging) were used in order to evaluate progression (Bosniak category reclassification) and stability, the latter being defined as remaining stable for a minimum of six months. Pathology reports were used as the reference to assess the malignancy rate of surgically resected cysts. A total of 152 cysts in 143 patients were included in the final analysis. Seven cysts (4.6%) were reclassified on follow-up studies, and mean time to progression was 20 months (range, 1 month to 4 years). Three cysts were surgically resected. All three were diagnosed as low-grade malignant renal cell carcinomas (RCCs): one clear cell RCC and two papillary RCCs. The remaining 145 cysts remained unchanged after a mean follow-up period of 28 months (range, 6 to 118 months). The progression rate in Bosniak category IIF cysts was low. Even lesions that were upgraded on follow-up remained stable, indicating an indolent behavior. Our data support the idea of conservative management of Bosniak IIF renal cyst.