Pituitary apoplexy

Last revised by Joe Cyriac on 19 Sep 2022

Pituitary apoplexy is an acute clinical condition caused by either haemorrhagic or non-haemorrhagic necrosis of the pituitary gland. Although presentation is variable, it typically comprises headache, visual deficits, ophthalmoplegia, and altered mental status. An existing pituitary macroadenoma is usually present (60-90%), but occasionally it happens in normal glands.

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The demographics generally follow that of pituitary macroadenomas.

Predisposing factors include 2:

As the gland suddenly enlarges it may cause compression of structures adjacent to the sella, and thus elicit a number of signs and symptoms, including 7,8:

  • sudden headache, including of 'thunderclap' nature, often retro-orbital or between eyes
  • loss of visual acuity with a chiasmal field defect
  • oculomotor palsies

Also, the patient may experience a decreased level of consciousness, hypopituitarism, Addisonian crisis 3, and subarachnoid irritation, the latter being secondary to haemorrhage.

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General features of pituitary apoplexy include enlargement of the pituitary gland, with or without bleeding. Macroscopic haemorrhage is common and occurs in about 85%. It shows peripheral enhancement around a non-enhancing infarcted centre. Surrounding oedema may be seen in the optic tracts and chiasm.

Routine CT is insensitive to pituitary apoplexy unless frank intracranial haemorrhage is present. The pituitary mass may be evident and may be hyperdense. Fluid-debris levels may also be evident.

MRI typically demonstrates a pituitary region mass.

  • T1: variable; in cases with haemorrhagic infarction, it is hyperintense due to blood (see ageing blood on MRI)
  • T2: variable signal
  • T1 C+ (Gd): enhancement variable; usually peripheral and may be difficult to identify due to intrinsic high T1 signal
  • DWI: restricted diffusion may be present in solid infarcted components 4

Immediate management includes prompt resuscitation, including administration of intravenous corticosteroids to avoid Addisonian crisis. Subsequent management is either neurosurgical or initially conservative 8. Generally, neurosurgical intervention is favoured, with a transsphenoidal approach to decompress the pituitary gland, although a conservative approach may be considered in carefully selected patients without visual loss and with normal consciousness 8. Pituitary apoplexy is usually associated with irreversible hypopituitarism mandating long-term hormone replacement therapy 8, and often ophthalmoplegia and visual loss 5.

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The differential is broadly that of a pituitary region mass, but as these patients present acutely with acute or subacute blood products, it can usually be limited to pituitary region masses with intrinsic high T1 signal.

  • necrotic/haemorrhagic pituitary macroadenoma
    • appearances are the same, but patients do not present acutely
    • whether or not the term apoplexy can be used in subacute presentations is debatable
  • adamantinomatous craniopharyngioma
    • calcification in 90%
    • usually in children
    • usually not acute presentation
  • Rathke cleft cyst
    • usually asymptomatic
    • no associated mass
    • spherical
  • dermoid/teratoma
    • usually have a fat component
    • unless ruptured, the presentation is usually insidious
    • if ruptured, locules of fat density/intensity material are often seen in the subarachnoid space

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