† These authors contributed equally.
Sclerosing stromal tumor is a rare benign neoplasm of the ovary. It occurs in women in the second-third decades of life and is generally hormonally inactive. It has nonspecific symptoms like menstrual irregularity, abdominal pain, amenorrhea, infertility and on imaging it is represented by a solid or cystic unilateral ovarian mass. We describe a case of a 17-year-old woman who presented with menstrual irregularity and pelvic pain. She underwent laboratory analysis including serum markers that were within normal ranges and a MRI which showed a solid mass measuring 4 cm of the right ovary. The patient underwent a laparoscopic surgery with the enucleation of the mass and, after the result of the frozen section examination, a conservative approach with preservation of the ovary was possible. Histopathological and immunohistochemical examinations confirmed the diagnosis of sclerosing stromal tumor of the ovary and allowed a differential diagnosis with other benign or malignant ovarian masses. SST of the ovary is a difficult diagnosis to make preoperatively. It commonly occurs in young women in whom ovarian conservation should be considered. Normal serum tumor markers and findings on imaging studies could suggest the diagnosis. However, the definitive diagnosis can only be made by histopathological examination of the removed tumor that can be treated successfully with fertility preserving surgery.