Bosniak IIF renal cysts: is there a malignancy potential?

Abstract

Objective:

To assess the radiological and clinical outcomes of patients with Bosniak IIF in our centre.

Methods:

We retrospectively analysed patients diagnosed with complex renal cysts classified as Bosniak IIF on contrast computed tomography imaging in our centre between March 2003 and September 2008. Surveillance images of Bosniak IIF were reviewed to determine radiological progression and clinical outcomes.

Results:

Forty patients with 42 category IIF cysts were included in our study (median age 68 years (range 38–88 years), median follow-up of 29 months (range 5–77 months)). Only one IIF cyst showed radiological progression to category III after a follow-up of 42 months (progression rate of 2.5%). Twenty-two cysts increased in size (mean 10.7 mm, range 3–41 mm), 10 cysts showed reduction in size (mean 7.9 mm, range 3–17 mm) and 10 cysts remained stable. Five patients died during surveillance and none of them had cause of death attributed to renal cancer or its complication.

Conclusions:

Our study has demonstrated that surveillance for Bosniak IIF cyst is a safe strategy. Furthermore, routine follow-up may not be required in all patients. However, longer term study is required before this can be confirmed.