A Rare Case of Bilateral Papillary Renal Neoplasm With Reverse Polarity on 18 F-FDG PET/CT in Native Kidneys of a Transplant Recipient.

Papillary renal neoplasm with reverse polarity (PRNRP) is a rare, low-grade renal tumor characterized by distinct histologic and molecular features. Bilateral involvement of native kidneys by PRNRP in renal transplant recipients is exceedingly rare, and its metabolic presentation on 18 F-FDG PET/CT has not been extensively documented in the literature. We present a unique case of bilateral native kidney PRNRP in a renal transplant recipient, which was incidentally detected on 18 F-FDG PET/CT and subsequently confirmed through histopathologic diagnosis after bilateral radical nephrectomy.