Primary hypothyroidism presenting as amenorrhoea and galactorrhoea with hyperprolactinaemia and pituitary enlargement.

The combination of amenorrhoea, galactorrhoea, and hyper-prolactinaemia in a young woman usually suggests that she has a prolactin secreting adenoma of the anterior pituitary gland. Primary autoimmune thyroid failure, however, is common in young women and may also be associated with hyperprolactinaemia and with galactorrhoea in those whose breasts have been exposed to oestrogen. Hypothyroidism in patients with the amenorrhoea and galactorrhoea syndrome is usually suggested by appropriate symptoms and clinical signs, and treatment with thyroxine renders the patient euthyroid, with resolution of the hyperprolactinaemia. We report on a patient who presented with amenorrhoea, galactorrhoea, hyperprolactinaemia, and suprasellar enlargement of the pituitary. Although she was clinically euthyroid, treatment with thyroxine resulted in resolution of her symptoms and hormonal and radiological abnormalities within six weeks. Patients with hyperprolactinaemia, with or without pituitary enlargement, should undergo assessment ofthyroid function even if clinically euthyroid !tg levonorgestel and ethinyloestradiol 30 Ltg) and had regular withdrawal bleeds. In 1983 after a planned pregnancy she delivered a healthy girl, but the puerperium had been complicated by severe postnatal depression and she remained amenorrhoeic for one year and had then had six months' oligomenorrhoea. Investigation elsewhere showed hyperprolactinaemria (prolactin concentrations of 762 and 1288 mU/l (normal <420 mU/l)) and a normal pituitary fossa on plain skull radiography. Her mother had been treated for hypothyroidism. Responses ofgrowth hormone, cortisol, prolactin and thyroid stimulating hormone to hypoglycaemia (0-1 U insulin kg), domperidone (10 mg intravenously), and thyrotrophin releasing hormone (200 pg intravenously) Minutes 0 20 30 60 90 120 Normal Insulin induced hypoglycaemia Glucose(mmol/l)