Endocrine Abstracts

A 16-year-old boy presented in September 2007 with headaches and droopy eye lid due to pituitary mass. His initial prolactin level was 320 832 mu/l which confirmed the diagnosis of macroprolactinoma.His glucagon test revealed him to be growth hormone deficient with normal thyroid function test and testosterone on the lower end of normal. He was then treated with cabergoline 0.5 mg once a week and growth hormone injection 0.8 mg once a day. In June 2008, his prolactin levels went down to 17 077 mu/l, but because the patient is experiencing intolerable side effects it was then switched to Quinagolide 75 mcg. Ten months later after initiation of dopamine agonist therapy his symptoms has improved and MRI shows a significant shrinkage of the tumour. His latest prolactin level was 2273 mu/l.

Prolactin secreting pituitary adenomas are the most common type of functional pituitary tumour. Treatment is indicated because of the consequences of infertility, gonadal dysfunction, osteoporosis and possibly tumour mass effect. First line of therapy is medical management with dopamine agonist. Medical therapy is effective in normalizing prolactin levels in more than 90% of patients.