Several different cells from the mesenchyme can give rise to sex-cord or stromal tumors. These include fibroblasts and endocrine cells. The symptoms of a sex-cord or stromal ovarian tumor can differ from other types of ovarian cancer. Common signs and symptoms include ovarian torsion, hemorrhage from or rupture of the tumor, an abdominal mass, and hormonal disruption. In children, isosexual precocious pseudopuberty may occur with granulosa cell tumors since they produce estrogen. These tumors cause abnormalities in menstruation (excessive bleeding, infrequent menstruation, or no menstruation) or postmenopausal bleeding. Because these tumors produce estrogen, they can cause or occur at the same time as endometrial cancer or breast cancer. Other sex-cord/stromal tumors present with distinct symptoms. Sertoli-Leydig cell tumors cause virilization and excessive hair growth due to the production of testosterone and androstenedione, which can also cause Cushing's syndrome in rare cases. Also, sex-cord stromal tumors occur that do not cause a hormonal imbalance, including benign fibromas, which cause ascites and hydrothorax. With germ cell tumors, sex cord-stromal tumors are the most common ovarian cancer diagnosed in women under 20.