RCC in Crossed Fused Ectopic Kidney: Rare of Rarest Entity

Primary renal cell carcinoma (RCC) in crossed fused renal ectopia represents a rare of rarest entity. Only nine cases were reported in the literature, including eight RCC and one transitional cell carcinoma. This report presents a case of a 75-years old male presented with incidentally discovered renal mass in a crossed fused ectopia. Careful preoperative planning and meticulous delineation of renal vasculature were performed to avoid unpredicted anatomy. Nephron-sparing surgery with preservation of the normal-functioning moiety was performed with uneventful postoperative course. These clinical, morphological and immunehistochemical features will be presented with a review of the current literature.