Monarch Disease Ontology term MONDO_0004255 (Wolffian adnexal tumor) is a benign or malignant epithelial neoplasm of probable Wolffian origin. It predominantly arises from the broad ligament and presents as a unilateral adnexal mass. Also known as: FATWO, Wolffian adnexal neoplasm, female adnexal tumor of probable Wolffian origin, female adnexal tumour of probable Wolffian origin.