Overview

• Benign tumours that arise sporadically from the anterior pituitary gland
• Aetiology → most occur sporadically, some cases have genetic association (Multiple Endocrine Neoplasia Type 1)
  • MEN 1 (3 P’s) ⇒ parathyroid, pituitary, pancreas. Typically presents as hypercalcaemia.

Classification:

• Size → Microadenoma ⇒ ≤10mm (1cm) or Macroadenoma ⇒ >10mm (1cm)
• Hormonal Status → Functional (secretes hormone) or Non-Functional (doesn’t produce hormone in excess)
  • Functional ⇒ prolactinoma (prolactin secreting), acromegaly (GH secreting), cushing’s disease (ACTH secreting)

Making Diagnosis

Clinical Features:

Non Functioning → panyhypopituitarism + bitemporal hemianopia + headache

• Bitemporal Hemianopia → due to pressure on optic chiasm
  • Upper quadrant defect > Lower quadrant defect = inferior chiasmal compression, typically pituitary tumour
  • Lower quadrant defect > Upper quadrant defect = superior chiasma compression, typically craniopharyngioma
• Panhyopituitarism → tumour may compress other parts of the pituitary gland
  • Non-Functioning tumours typically present with generalised hypopituitarism
  • Low ACTH ⇒ tiredness, postural hypotension
  • Low FSH/LH ⇒ amenorrhoea, infertility, loss of libido
  • Low TSH ⇒ feeling cold, constipation
• Headache

Prolactinoma

• Women → amenorrhoea, infertility, galactorrhoea, osteoporosis
• Men → impotence, loss of libido, galactorrhoea
• Other Macroadenoma Signs → headache, visual disturbances, symptoms of hypopituitarism

Acromegaly ⇒ increase in shoe and hand size, large tongue, excessive sweating, OSA.