Spontaneous Cerebrospinal Fluid Rhinorrhea from a Prolactin-Secreting Pituitary Macroadenoma

Cerebrospinal fluid (CSF) rhinorrhea is a rare complication of macroprolactinomas that, in the vast majority of cases, is subsequent to either medical or surgical intervention. Here, we present the successful management of a rare case of spontaneous, noniatrogenic CSF rhinorrhea in a patient with an untreated macroprolactinoma. A 27-year-old man with no significant medical history presented with six months of persistent CSF rhinorrhea, which was confirmed by testing for beta-2-transferrin. He had had decreased libido since adolescence and impaired growth of secondary sexual characteristics. Workup revealed an elevated prolactin level, and imaging demonstrated erosion of the anterior sellar floor and soft tissue within the sphenoid sinus, concerning for tumor. The patient underwent surgical repair of the CSF leak via a transnasal transsphenoidal approach, with resection and biopsy of tumor material within the sinus. No tumor was noted within the sella itself. The patient tolerated the procedure well and had subsequent normalization of his prolactin level with no further CSF egress. Spontaneous noniatrogenic CSF rhinorrhea, although rare, should be considered in the differential diagnosis of invasive pituitary macroadenomas, especially prolactinomas. The mechanism of CSF leak from a prolactinoma is not completely understood, but the CSF leak should be urgently repaired through a transnasal transsphenoidal approach. Concurrently, tumor resection should be performed and a postoperative lumbar puncture or lumbar drain should be considered to reinforce the skull base reconstruction.