Occult invasive pituitary adenoma predisposing to fatal bacterial meningitis.

Pituitary adenomata are benign neoplasms which usually grow slowly and present with manifestations relating to an associated endocrinopathy or visual disturbance. Rarely these neoplasms will demonstrate a more aggressive behavior with extracranial extension and symptoms of upper airway obstruction or anosmia. Several reported cases suggest that although these neoplasms behave aggressively the overall survival and prognosis for these patients remains good. We present the clinical and postmortem findings of an occult invasive pituitary adenoma leading to the development of bacterial meningitis, coma and death. This communication stresses the necessity for the early diagnosis and treatment of the invasive adenomata to prevent the development of potentially fatal infectious sequelae.