Fig. 2

A 71-year-old male patient complaining of right loin pain. Axial T2-WI of the right kidney (A) showed an upper polar cystic lesion of heterogeneous high SI, multiple septa, multiple parenchymal cysts of fluid SI, and a small hemorrhagic one. This cystic lesion showed heterogeneous low SI at axial T1WI (B) and showed non-enhancing wall and non-enhancing septa (wall and septal thickness were 3 mm) at axial corticomedullary (C), nephrographic (D), and coronal DCE-MRI images (E). By consensus, cystic lesion was initially categorized as Bosniak class III in view of thick wall and multiple irregular thickened septa. As version 2019 defines thickening at 3 mm, the lesion was downgraded to Bosniak class IIF. The patient underwent right partial nephrectomy, and histopathology was a hemorraghic cyst