Abstract
A 82-year-old woman was referred to our hospital with complaints of weight loss, loss of appetite, abdominal pain and a palpable pelvic mass. Abdominal imaging revealed a tumour at the upper pole of the right kidney with a maximum diameter of 8 cm and a second tumour in the pelvis, mostly solid, with a maximum diameter of 16 cm, that seemed to originate from the left ovary. As she was initially considered to have two distinct tumours, through a single transabdominal incision, she simultaneously underwent right radical nephrectomy and also bilateral salpingo-oophorectomy for the tumour that originated from the left ovary. Histopathological examination showed that the tumour in the right kidney was a clear-cell renal cell carcinoma (RCC) (stage pT3a, Fuhrman grade 2). The ovarian tumour proved to be an ovarian fibroma that included a circumscribed focus with a diameter of 0.7 cm which was a metastasis from the kidney tumour. Immunohistochemistry contributed significantly to the diagnosis, as the focus showed strong and diffuse expression of CD10 and RCC antigen, which are reliable markers of RCC. With less than 30 reported cases in the literature, it is very important to differentiate ovarian metastasis of RCC from primary ovarian tumour due to different treatment alternatives and prognosis.