Female adnexal tumor of probable Wolffian origin (FATWO) is a rare neoplasm which is usually considered as benign, although in some cases metastasis or recurrences have been reported even after a long interval following the initial diagnosis. Preoperative diagnosis of FATWO is very difficult because of the rarity of the disease and the limited literature available. In this case report, we present a case of FATWO arising from the ovary and review the literature based on the clinical characteristics and management of this rare condition. A 51- year- old postmenopausal woman was referred to our clinic for evaluation of an adnexal mass. After diagnostic evaluation, the patient underwent explorative laparotomy. Intra-operatively, a solid- cystic mass was found in the right ovary, the rest of the abdomen and the pelvis were normal. The ovarian mass was removed and examined with frozen-section (FS). When the frozen section proved negative for malignancy, total abdominal hysterectomy and bilateral adnexectomy were performed. The anatomic study revealed a well-capsulated mass which was 3.5×1.5 cm in diameter. Based on pathological and immunohistochemical results, the final diagnosis was concluded to be FATWO. Adjuvant therapy was not administered. Te patient was followed up after discharge from the hospital. One year after surgery she was asymptomatic. No evidences of recurrence were observed throughout this period. Although FATWOs are rare tumors, they should be kept in mind in women with an abdominal mass. They can present diagnostic difficulties and the diagnosis is based on the exclusion of other neoplasms. FATWO has malignant potential, after the initial surgical treatment patients should be appropriately followed up for possible recurrence and metastasis.

Keywords: Neoplasm, Wolffian adnexal tumor, FATWO, ovary, benign