A benign adenofibroma characterized by the presence of epithelial cells which contain intracytoplasmic mucin and a fibrotic stroma. A representative example is the ovarian mucinous adenofibroma. Cases with epithelial atypia described in the ovary lacking stromal invasion are designated as borderline mucinous adenofibromas and have a low grade malignant potential. The disease is mucinous adenofibroma (MONDO_0002398, a Monarch Disease Ontology term).