International Journal of Academic Health and Medical Research (IJAHMR)   Year: 2021 | Volume: 5 | Issue: 4 | Page No.: 123-125 Retroperitoneal Schwannoma Simulating An Ovarian Tumor (Case Report) Youness ammor, Mehdi laaouze, karam mohammed saoud, Mamouni Nisrine, Sanae Errarhay, Bouchikhi Shehrazad, Abd Aziz Banani, A.Bensalah; M. Boubou Abstract: Schwannoma is a tumor that develops on the Schwann cells. It is a very rare tumor both in terms of its frequency and its retroperitoneal location. Its presentation is varied and its preoperative diagnosis is difficult. Although the vast majority of schwannomas are benign, there are malignant forms frequently associated with Von Recklinghausen syndrome. Its diagnosis is histological and its surgical treatment consists in a complete removal of the mass because of a tumor degenerative risk.We report a case of a 64 year old female patient, followed for chronic pelvic pain associated with digestive signs, ultrasound and CT scan showed a pelvic retroperitoneal mass of 8x 6 cm of great axis. The removal was performed by laparotomy. The histological and immunological study concluded to a benign schwannoma. Through a review of the literature we recall the frequency, diagnosis, imaging data, treatment and evolution of this rare tumor.