Ectopic Sphenoid Sinus Prolactinoma Associated With Empty Sella and Recurrent Meningitis Treated Successfully With Cabergoline

Ectopic pituitary adenomas (EPA) are tumors that reside outside the sella turcica and are not connected to the pituitary gland. We present a case of a 62-year-old female who was hospitalized for recurrent meningitis. Workup, including magnetic resonance imaging (MRI) of the brain, computed tomography (CT) of the sinuses, and follow-up MRI of the sella turcica, revealed an 8 millimeter (mm) mass in the right posterior sphenoid sinus with an empty sella turcica and no evidence of a sellar mass. The mass was biopsied, with pathology results showing findings of a pituitary adenoma staining positive for prolactinoma. Subsequent hormonal workup revealed an elevated prolactin level of 128.4 nanograms per milliliter (ng/mL) without evidence of additional hormonal co-secretion or hypopituitarism. The patient was started on cabergoline with eventual normalization of the prolactin level and regression of the adenoma on follow-up imaging. EPAs are rare and thus treatment guidelines have not been established. Our case report not only highlights a case of successful treatment of ectopic prolactinoma with dopamine agonist therapy but also calls attention to the uncommon co-existence of EPAs and empty sella turcica and meningitis as an extremely uncommon presentation of EPAs.