Spontaneous feminization and menstrual function developing during puberty in Turner's syndrome.

An 18-year-old patient with Turner's syndrome presented with cyclical vaginal bleeding and spontaneous development of secondary sexual characteristics. She demonstrated classic features of Turner's phenotype, and a culture of blood lymphocytes revealed a 45,XO karyotype. The patient's plasma and urinary estrogen concentrations were similar to those in normal adult women in the late proliferative phase. In contrast, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were elevated to values seen in postmenopausal women. Dynamic testing revealed no estrogen response to human menopausal gonadotropin (/MG) and a paradoxical fall in estrogen after administration of human chorionic gonadotropin (hCG). Administration of luteinizing hormone-releasing hormone (LH-RH) resulted in an exaggerated response of both gonadotropins. Dilatation and curettage revealed endometrial hyperplasia, and a laparotomy revealed the presence of 2 gonadlike structures. The histologic diagnosis was lutein cyst. Karyotyping of lymphocytes, skin from the abdominal incision, and tissue from both gonadal structures revealed a 45,XO karyotype without evidence of mosaicism.