Ovarian Hyperthecosis in a 12-year-old Chinese Girl Presenting With Virilization.

All girls presenting with virilization (which signifies severe hyperandrogenism) warrant thorough investigation. Ovarian hyperthecosis (OHT) is a rare cause of virilization in premenopausal women. Here, we report the case of a previously healthy 12-year-old Chinese girl with signs of virilization at puberty. Her serum total testosterone was elevated at 5.1 nmol/L (146.97 ng/dL) (normal: <1.4 nmol/L, <40.35 ng/dL). Workup for Cushing syndrome, sex development disorders, congenital adrenal hyperplasia, and adrenal and ovarian androgen-secreting tumors was unrevealing. Ovarian and adrenal venous sampling demonstrated ovarian hyperandrogenism without lateralization. Ovarian biopsy revealed nests of theca cells in the stroma of the right ovary, substantiating the diagnosis of OHT. A single dose of a GnRH analog resulted in the complete suppression of serum testosterone, supporting the diagnosis of OHT. Medical treatment with hormonal replacement therapy normalized serum testosterone levels. Our case report illustrates the diagnostic approach to virilization among girls at puberty and the diagnosis of OHT as the underlying pathology.