Abstract
Primary renal cell carcinoma (RCC) in crossed fused renal ectopia represents a rare of rarity entity. Only eight cases were reported in the literature, including seven RCC and one transitional cell carcinoma. This report presents a case of a 39-years old female 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 immune-histochemical features will be presented with a review of the current literature.