Pituitary Adenoma
A pituitary adenoma is a growth on the pituitary gland, classified as functioning (hormone-producing) or non-functioning, and by size as a microadenoma (under 1 cm) or macroadenoma, per current JAMA reviews.
Symptoms
Non-functioning adenomas often cause no symptoms until they're large enough to press on nearby structures (headache, vision changes) or disrupt normal pituitary function. Functioning adenomas cause symptoms specific to whatever hormone they overproduce (prolactin, growth hormone, ACTH).
Causes and risk
Most arise sporadically; about 5% are familial, linked to genetic syndromes like MEN1 or Carney complex.
How it is evaluated
A full hormonal panel (checking for both hormone excess and deficiency), dedicated pituitary-protocol MRI, and visual field testing when the tumor is near the optic chiasm, per Endocrine Society incidentaloma guidance.
Treatment
Dopamine agonists are first-line for prolactinomas specifically. Transsphenoidal surgery is first-line for other functioning or symptomatic tumors; radiation is reserved for recurrent or refractory disease.
When to seek care
Pituitary apoplexy -- sudden severe headache, vision loss, and altered consciousness from bleeding or infarction of the tumor -- is a neurosurgical and endocrine emergency requiring immediate hospital care.