Collision Tumor of the Ovary Involving Sertoli-Leydig Cell Tumor and High-Grade Serous Carcinoma—Report of the First Case

We report a collision tumor in the ovary of a 60-yr-old woman composed of high-grade serous carcinoma and Sertoli-Leydig cell tumor. Collision tumors in the ovary are rare and to the best of our knowledge, combination of ovarian high-grade serous carcinoma and Sertoli-Leydig cell tumor has not been described before.