Presentation of pituitary tumours

Pituitary tumours may present because of either their mass their or endocrine effects.

Mass effects are usually due to large tumours and include:

• headache - non-specific
• visual field defects - from pressure on the inferior of the optic chiasm; begins as a superior temporal quadrantanopia progressing to bitemporal hemianopia
• cavernous sinus compression - resulting from lateral extension of the tumour into the cavernous sinus. Most often produces a III nerve palsy; may also compress the IV and VI nerves, and produce sensory loss in the first and second divisions of cranial V.
• rarely, erosion of the mass through the sphenoid sinus produces a CSF rhinorrhoea

Endocrine effects may be due to oversecretion of specific hormones, usually one, especially caused by small tumours:

• hyperprolactinaemia - most common
• gigantism / acromegaly - from GH hypersecretion
• Cushing's disease - from ACTH hypersecretion - presents as Cushing's syndrome
• rarely, hypersecretion of TSH, FSH, LH

Or due to undersecretion of specific hormones, presenting as panhypopituitarism. This may be associated with compression of the pituitary gland from a large tumour, or may result from small tumours.

Pituitary adenomas may also present as pituitary apoplexy.