Abstract Mature cystic teratomas, or dermoid tumors, are the most common benign ovarian neoplasms in young women. Malignant transformation is rare, and occurs in less than 2% of the cases. The heterogeneous histological composition of these tumors may be responsible for the occasional elevation of various tumor markers, such as Ca19-9 and Ca125. We describe one case of mature cystic teratoma in a 50-year old wo...