Bennett JA, Ritterhouse LL, Furtado LV, et al. - Experts assessed the morphological, immunohistochemical, and molecular peculiarities of 15 tumors of probable Wolffian origin. Individuals ranged from 32 to 69 years and tumors from 1.8 to 30 cm. These patterns were observed—tubular in all tumors, solid in 11/15, sieve-like in 7/15, and reticular in 1/15 tumors. A myxoid background and eosinophilic luminal secretions were seen in 3/15 and 11/15 of tumors, respectively. Low-grade nuclear atypia was seen in most of the tumors (12/15), while three exhibited foci with scattered high-grade atypia. For pankeratin and TTF-1 tumors were respectively positive and negative. In 2/10, 3/15, and 1/15 of tumors, respectively, EMA, GATA3, and PAX8 were positive. CD10, SF-1, calretinin, inhibin, ER, PR, cytokeratin 7, and WT1 were variably expressed. Pathogenic mutations were rare, comprising STK11, APC, and MBD4. In the three tumors with STK11 mutations and a myxoid background, copy number alterations were identified. Hence, this data shows that female adnexal tumors of probable Wolffian origin are morphologically and immunohistochemically various, however, it seldom harbor pathogenic mutations. Nonetheless, their lack of mutations compared with their mimickers could be a relevant tool in diagnostically complex cases.