Introduction: Although many intraabdominal cancers frequently metastasize to ovaries, renal cell carcinoma rarely metastasizes to the ovary and can cause significant diagnostic problems because in addition to the same histological features similar to primary tumors of the ovary, they are usually diagnosed ith a relatively long time interval from the primary cancer. On the other hand, considering the different prognosis and treatment, it is important to distinguish between primary ovarian tumors and ovarian metastases from RCC. In this study, a rare case of renal cell carcinoma metastasizing to the ovary in a 67-year-old woman was reported.
Case Presentation: The patient was a 67-year-old woman with a history of right RCC who had referred to the gynecology clinic for follow-up. Ultrasound of the left adnexa revealed a solid cystic focus with internal vascularity measuring 48 x 63 mm, and CT scan revealed a  well circumscribe cystic solid foci with internal vascularity with dimensions of 48×63 mm and in CT scan, the cystic solid mass with a heterogeneous density of 43×61 mm was reported. After hysterectomy and salpingo-oophorectomy, in histopathological evaluation, neoplastic lesion was observed with solid growth pattern made of atypical and relatively pleomorphic cells with wide and bright cytoplasm and rounded nuclei with irregular borders, glandular differentiated foci and large areas of bleeding and necrosis, which was in favor of metastatic clear cell renal cell carcinoma and was confirmed by immunohistochemistry staining.
Conclusion: Renal cell carcinoma with unpredictable clinical behavior is unpredictable and can metastasize to unusual sites. Although metastasis of renal tumor to ovary is rare, but an ovarian tumor should be suspected if there is a history of primary renal tumor.