Release of prolactin, thyrotropin, and growth hormone in women with cyclical mastalgia and fibrocystic disease of the breast.

Prolactin (PRL), thyroid stimulating hormone (TSH) and growth hormone (GH) response to metoclopramide and TRH was investigated in seven women with fibrocystic disease and cyclical mastalgia, in eight similar patients without mastalgia, and in six normal controls. The basal PRL level was significantly elevated in patients with cyclical mastalgia (P less than 0.025). PRL and TSH response to metoclopramide did not differ significantly between the three groups, indicating that decreased dopaminergic tone is not the cause of elevated basal PRL level in cyclical mastalgia. PRL and TSH response to TRH and the abscent GH response to both metoclopramide and TRH further indicate that the hypothalamicpituitary axis is not primarily disturbed in cyclical mastalgia. The basal GH level was elevated in patients with fibrocystic disease with or without mastalgia. The increased basal GH secretion is not believed to be directly involved in cyclical mastalgia, but may be of importance in fibrocystic disease.