Pituitary apoplexy

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What this article covers

• Overview

  Definition: pituitary apoplexy is sudden hemorrhage or infarction of a pituitary adenoma, most often a nonfunctioning macroadenoma that has outgrown its blood supply.

• Epidemiology

  Occurs almost exclusively in the setting of a pituitary adenoma: most substrate tumors are nonfunctioning macroadenomas, which are often clinically silent until the apoplectic event.

• Risk factors

  Underlying pituitary adenoma, particularly a macroadenoma: the enlarging, vascularly fragile tumor is the substrate for hemorrhage or infarction.

• Pathophysiology

  A rapidly growing or vascularly compromised adenoma outgrows its blood supply, leading to hemorrhagic infarction of the tumor and adjacent normal pituitary tissue.

• Clinical features

  Sudden, severe headache is the hallmark and near-universal presenting symptom, often described as the worst headache of the patient's life (a thunderclap pattern).

• Differential diagnosis

  Subarachnoid hemorrhage: also a thunderclap headache, but without the bitemporal visual field defect of chiasm compression, and confirmed by noncontrast CT or lumbar puncture for xanthochromia rather than a sellar mass.

• Diagnosis

  The diagnosis is established clinically, by the acute triad of severe headache, visual disturbance or ophthalmoplegia, and biochemical evidence of hypocortisolemia in a patient with a pituitary mass…

• Management

  First, if adrenal insufficiency is suspected (relative hypotension, hyponatremia, or any evidence of hypocortisolemia), give immediate IV hydrocortisone without waiting for confirmatory testing…

• Complications

  Acute adrenal crisis and cardiovascular collapse from unrecognized or inadequately treated ACTH deficiency, which can be fatal.

• Prognosis

  Outcome is closely tied to time to treatment, particularly for visual recovery, which is more likely when decompression is performed promptly after visual loss develops.

• Prevention

  Evaluate for pituitary hormone deficiency in every patient with a known pituitary tumor, regardless of symptoms, with FSH, LH, cortisol, TSH, free T4, and total testosterone in men, so that a baseline is available if apoplexy later occurs.