AKT · Endocrine/Pituitary & ADH

Pituitary tumours

Adenoma of the pituitary (functioning or non-functioning) ± mass effect

Overview

Pituitary adenomas — functioning (prolactinoma, GH→acromegaly, ACTH→Cushing's disease, rarely TSH) or non-functioning. They present through hormone excess, hormone deficiency (compression of normal gland) or mass effect (bitemporal hemianopia from optic chiasm compression, headache, cavernous sinus involvement). Pituitary apoplexy is the acute haemorrhage/infarction.

Recognise

Mass effect: BITEMPORAL HEMIANOPIA (optic chiasm), headache, cranial-nerve palsies (cavernous sinus), hypopituitarism
Functioning syndromes: galactorrhoea/amenorrhoea (prolactin), acromegaly (GH), Cushing's disease (ACTH)
Pituitary apoplexy: sudden severe headache, visual loss, ophthalmoplegia, collapse

Red flags

Pituitary apoplexy → emergency (steroids + neurosurgery)
Progressive visual field loss → urgent surgical decompression

Differentials & how to tell them apart

Craniopharyngiomasuprasellar, calcified, children/young adults, bitemporal hemianopia + growth failure

Meningioma / Rathke cleft cystother parasellar masses on imaging

Prolactinoma vs non-functioning adenomavery high prolactin (prolactinoma → dopamine agonist) vs mildly raised (stalk effect → surgery)

Investigations

MRI pituitary; visual fields/acuity; full pituitary hormone profile (excess and deficiency); prolactin (and beware the hook effect).

Management

Prolactinoma → dopamine agonist; others → transsphenoidal surgery

1Characterise function (excess/deficiency) and mass effect (fields, MRI). PROLACTINOMAS are treated medically (dopamine agonist); other functioning/compressive tumours are surgical.Gate: Confirm it is not a prolactinoma before operating — a very high prolactin means dopamine agonist (medical) first, whereas a mild rise with a big tumour is stalk compression needing surgery; apoplexy needs urgent steroids + neurosurgery
2Transsphenoidal surgery ± radiotherapy; replace deficient axes; lifelong endocrine and imaging follow-up.

Dopamine agonist (prolactinoma) — medical first-line for prolactin-secreting tumours

Transsphenoidal surgery — for non-functioning macroadenomas with mass effect, GH/ACTH tumours, apoplexy

Key points

Bitemporal hemianopia + a sellar mass = pituitary tumour. The single most useful triage: very high prolactin (→ medical) vs everything else (→ surgery). Apoplexy is the emergency.

Monitor & prognosis

Fields, MRI, pituitary axes.

Good; depends on type/size.

Source: Society for Endocrinology; neurosurgery guidance