A benign adenofibroma characterized by the presence of serous secretory cells and minute cystic spaces filled with watery fluid. A representative example is the ovarian serous adenofibroma. Cases with epithelial atypia described in the ovary lacking stromal invasion are designated as borderline serous adenofibromas and have a low grade malignant potential. The disease is Monarch Disease Ontology term MONDO_0024886 (serous adenofibroma).