Pituitary Abscess

Abstract

Intracranial infectious pathologies mainly include meningitis, encephalitis, brain abscesses, and ventriculitis. Infectious processes located in the sellar region are rare, and even rarer when abscesses limited to the pituitary gland itself are considered. Pituitary abscesses represent less than 1 % of all pituitary lesions. Pathophysiology of pituitary abscesses consists in a contiguous spreading of a local infection arising from the sphenoid sinus, the surrounding meninges of the basal cisterns or a thrombophlebitis of the cavernous sinus. Direct hematogenous seeding to the gland itself also exists. Patients with pituitary abscess usually present with either sudden or long-lasting headaches or anterior pituitary deficiency. Fever is rarely present, and symptoms of bacteremia are usually absent. Other symptoms related to the mass effect of large abscesses may be observed, such as visual disturbances and diabetes insipidus. Pituitary abscesses are primary lesions of the pituitary gland, but about one-third develop on a pre-existing lesion such as pituitary adenoma, Rathke cleft cyst (RCC), or craniopharyngioma. Necrosis and hemorrhage in pituitary adenoma may facilitate their secondary infection (Fig. 42.1). Abscesses may also complicate transsphenoidal surgery.