Primary hypothyroidism and ovarian activity evidence for an overlap in the synthesis of pituitary glycoproteins. Case report.

A 14-year-old girl presented with precocious sexual development, galactorrhoea and symptoms and signs suggestive of hypothyroidism. On physical examination a tumour was found in the lower abdomen. Serum gonadotrophins, especially luteinizing hormone, serum thyroid stimulating hormone and prolactin were elevated. Measurement of thyroid hormones and additional thyroid function tests confirmed the diagnosis of primary hypothyroidism. Ultrasound investigation revealed the mass in the lower abdomen to be of a cystic nature and to originate from the right ovary. Following the institution of thyroid substitution therapy, all symptoms disappeared, biochemical and hormonal abnormalities returned to normal and the ovarian size decreased to normal. A hypothesis is presented for non-specific pituitary glycoprotein hormone synthesis secondary to the hypothyroidism, as the cause of the syndrome.