Article Text

PDF

A 35 year man with acromegaly and neck stiffness

Statistics from Altmetric.com

Q1: What is the diagnosis?

The diagnosis is pituitary apoplexy. This is abrupt destruction of pituitary tissue resulting from infarction or haemorrhage into the pituitary, usually into an undiagnosed tumour.1 Common predisposing factors are listed in box 1.

Box 1: Pituitary apoplexy—predisposing causes2

  • Haemorrhagic infarction of a pituitary tumour.

  • After obstetric haemorrhage.

  • Diabetes mellitus and diabetic ketoacidosis.

  • Radiation therapy.

  • Anticoagulant therapy.

  • Bleeding disorders.

  • Head trauma.

  • Raised intracranial pressure.

  • Drugs: bromocriptine, clomiphene, thyrotrophin releasing hormone, triple bolus test, gonadotrophin releasing hormone, luteinising hormone releasing hormone analogue (goserelin), isosorbide, chlorpromazine, oestrogens.

  • Carotid angiography and pneumoencephalography.

  • Mechanical ventilation.

  • Cardiac surgery, lumbar laminectomy, haemodialysis.

Clinically pituitary apoplexy presentation may vary from asymptomatic “silent” pituitary apoplexy to catastrophic endocrine emergency with blindness, coma, and haemodynamic instability. Clinical features are outlined in box 2.

Box 2: Pituitary apoplexy—clinical features

  • Headache: retro-orbital, frontal, or diffuse.

  • Visual impairment: decreased visual acuity, visual field defects (most commonly bitemporal hemianopia, optic atrophy leading to blindness).

  • Ophthalmoplegia: III, IV, VI nerve paresis.

  • Facial pain and loss of corneal reflex: due to ophthalmic V nerve involvement.

  • Nausea, vomiting: due to meningism or raised intracranial pressure.

  • Meningism: due to blood or necrotic tumour in subarachnoid space.

  • Altered mentation, ranging from mild lethargy to coma.

  • Hemiparesis and seizures: due to entrapment of the internal carotid artery in cavernous sinus or vasospasm due to subarachnoid haemorrhage (SAH).

  • Anosmia: due to olfactory nerve compression.

  • Epistaxis and cerebrospinal fluid rhinorrhoea: because of erosion of haemorrhage through sphenoid sinus into the nasal cavity.

  • Proptosis and eyelid oedema: caused by cavernous sinus obliteration.

  • Hypothalamic compression: disturbed sympathetic autoregulation leading to abnormalities in thermoregulation, respiration, blood pressure, and cardiac rhythm.

  • Fever.

Numerous endocrinopathies both transient and permanent, may result from pituitary apoplexy. Partial or complete hypofunctioning of the pituitary appears to be the rule (see box 3).

Q2: What are the two most critical alternative diagnoses?

Two most critical alternative diagnoses in this patient are aneurysmal SAH and bacterial meningitis. Pituitary apoplexy in its most classic presentation may mimic SAH. Both present with sudden onset of severe headache, impaired consciousness, and meningeal signs. Similarly both may have sentinel headache, although the interval between the onset of headache and development of mental status changes tends to be shorter in SAH. Bilateral third cranial nerve paresis favours pituitary apoplexy; unilateral deficits may be seen in both.

Box 3: Pituitary apoplexy—endocrinopathies3

  • Hypogonadism: 100%

  • Growth hormone deficiency: 88%

  • Hyperprolactinaemia: 67%

  • Acute adrenal insufficiency: 66%

  • Hypothyroidism: 42%

  • Diabetes insipidus: 3%

Differentiating between pituitary apoplexy and bacterial meningitis may likewise be difficult because meningeal signs, altered mental status, fever, and headache are features of both. Ophthalmological findings or hemiparesis, if present, favour the diagnosis of pituitary apoplexy.

Mid-brain infarction (basilar artery occlusion) and cavernous sinus thrombosis, although less common, also may need exclusion.

Q3: What is the role of lumbar puncture in this patient?

Lumbar puncture is an unreliable means of differentiating pituitary apoplexy from SAH, since high red cell count and xanthochromia may sometimes be seen in pituitary apoplexy. Pleocytosis and raised cerebrospinal fluid proteins are common to both bacterial meningitis and pituitary apoplexy, and do not provide much assistance in distinguishing between them. Moreover in suspected pituitary apoplexy lumbar puncture may be dangerous, because it may precipitate uncal herniation. Computed tomography and magnetic resonance imaging are most likely to be helpful by demonstrating a sellar mass even if evidence of acute haemorrhage is not obvious (see box 4).4

Box 4: Neuroimaging in pituitary apoplexy5

Computed tomography
  • Computed tomography of the head is most useful in the acute setting (24–48 hours).

  • 1.5 mm thin sections in coronal plane through pituitary fossa with intravenous contrast are highly sensitive.

  • High density or inhomogeneous gland, with or without evidence of subarachnoid blood ring enhancement or a high density fluid level, may be seen.

Magnetic resonance imaging
  • Acute haemorrhage (<7 days): hypointense or isointense to brain on T1 and T2 weighted images.

  • Subacute stage (7–14 days) increased intensity in periphery of the haematoma (owing to haemoglobin breakdown products such as methaemoglobin), with centre remaining hypointense.

  • Chronic stage (>14 days) entire haematoma appears bright on T1 and T2 images.

Follow up

The patient was managed with intravenous hydrocortisone and other supportive measures. Emergency transsphenoidal removal of a necrotic and haemorrhagic pituitary macroadenoma was done. Immunohistochemistry revealed growth hormone secreting adenoma. He made a rapid symptomatic recovery and features of meningism subsided over the next two days. Further endocrinological evaluation is planned to determine the nature and degree of hormone deficits.

Final diagnosis

Pituitary apoplexy.

References

View Abstract

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.