Abstract
In this case we present a diagnostic challenge of a renal cyst that has radiological features that were hard to differentiate between infection and malignancy. Our patient presented with suspicious infected right renal cystic lesion, 4 months after undergoing complicated appendectomy with limited right hemicolectomy. This cyst was diagnosed previously as Bosniak IIF and was assigned for follow up every 6 months. Radiological assessment was in favor of abscess formation however it was also concerning for infected renal cell cancer. As only drainage may cause seeding of potential cancer cells, right partial nephrectomy was done. Histopathology was papillary cancer. Bosniak IIF cystic lesions are still managed with follow up, however this type of cystic lesions carries considerable risk of malignancy according to most recent studies; we are presenting this case report to emphasis this fact and to highlight the importance of proper diagnosis and treatment choice.