•FATWOs are rare gynecologic neoplasms of low malignant potential derived from mesonephric (Wolffian) duct remnants.•FATWOs have diverse presentations from vague abdominal symptoms to incidental diagnosis.•In general, FATWOs require no additional management beyond initial surgical intervention.
Keywords: Adnexal mass; Benign; FATWO; Wolffian duct.
© 2020 The Authors.