Background: A 31-year-old woman presented 12 months after discontinuing the oral contraceptive pill with progressive headache to her primary-care physician. She had previously presented with irregular menses to her obstetrician-gynecologist 4 months after discontinuing the oral contraceptive pill. Her serum prolactin levels were 153 microg/l and a pituitary MRI revealed a 13 mm intrasellar mass consistent with an adenoma. The patient was given 0.5 mg cabergoline twice weekly, and after 6 weeks her prolactin levels fell to 31 microg/l. After 6 months, however, she complained of persistent frontal headache and a repeat MRI revealed that the adenoma had increased in size to 16 mm. The patient was referred to an endocrinologist for further evaluation.
Investigations: Serum insulin-like growth factor 1 levels and growth hormone levels measured 2 h after ingestion of 75 g of oral glucose.
Diagnosis: Acromegaly and hyperprolactinemia caused by a mixed-cell adenoma, secreting growth hormone and prolactin.
Management: Trans-sphenoidal surgery followed by medical therapy with 20 mg intramuscular octreotide-LAR monthly.