Hormonal effects
Many benign tumors produce hormone-like substances, which can cause hormonal disturbances in the patient. Thecal cell tumors cause menstrual irregularities due to estrogen production; it can also lead to precocious puberty, menorrhagia, endometrial hyperplasia, and endometrial carcinoma.
Virilization (excessive hair growth, acne, voice changes, clitoris enlargement), breast atrophy, and amenorrhea are caused by androgen producing tumors such as Leydig Sertoli cell tumor. Hyperthyroidism is another endocrinal disturbance caused by a dermoid cyst if it has thyroid tissue (Struma ovarii). It can also be caused by beta Human chorionic gonadotrophin (beta hCG) producing tumors such as yolk sac tumor and choriocarcinoma because beta hCG resembles beta subunit of thyroid stimulation hormone, and stimulates the thyroid gland to produce thyroid hormone, leading to hyperthyroidism.