Prolactinoma

Prolactinomas are a type of pituitary adenoma, a benign tumour of the pituitary gland.

Pituitary adenomas can be classified according to:

• size (a microadenoma is <1cm and a macroadenoma is >1cm)
• hormonal status (a secretory/functioning adenoma produces and excess of a particular hormone and a non-secretory/functioning adenoma does not produce a hormone to excess)

Prolactinomas are the most common type and they produce an excess of prolactin.

Features

• excess prolactin in women
  • amenorrhoea
  • infertility
  • galactorrhoea
  • osteoporosis
• excess prolactin in men
  • impotence
  • loss of libido
  • galactorrhoea
• other symptoms may be seen with macroadenomas
  • headache.
  • visual disturbances (classically, a bitemporal hemianopia (lateral visual fields) or upper temporal quadrantanopia)
  • symptoms and signs of hypopituitarism

Diagnosis

• MRI

Management

• in the majority of cases, symptomatic patients are treated medically with dopamine agonists (e.g. cabergoline, bromocriptine) which inhibit the release of prolactin from the pituitary gland
• surgery is performed for patients who cannot tolerate or fail to respond to medical therapy. A trans-sphenoidal approach is generally preferred unless there is a significant extra-pituitary extension