Malignant Female Adnexal Tumor of Probable Wolffian Origin (FATWO): A case report and review for the literature

•Of the fewer than 100 FATWO case reports published, at least 25 reports have metastatic quality.•Very little information regarding optimal management of FATWO is known; immunohistochemical stains may help guide therapy.•FATWO may be more of a low malignant potential entity, and patients with the diagnosis should be followed closely.