FRI321 Aggressive Prolactinoma Empirically Treated With Cabergoline Leading To Rapid CSF Leak

Disclosure: A. Yau: None. T. Reisman: None. Over two-thirds of pituitary tumors are prolactinomas. These are discovered as a result of symptoms of hypogonadism, menstrual irregularities, infertility or galactorrhea, as well as symptoms of mass effects including visual field deficit or acute severe headaches.(1) A more rare subgroup, aggressive prolactinomas, in which the tumors are radiographically invasive and show resistance to dopamine agonist treatment as well as surgery, account for 10% of all hypophyseal neoplasia. (2) During medical treatment of prolactinomas, there is a known rare complication of CSF rhinorrhea; recorded time of onset of leak following treatment ranges from 14 days to 5 years.(3) We present a case in which a patient with an aggressive prolactinoma rapidly developed a CSF leak within 48 hours of starting cabergoline treatment. Case: A 36-year-old male with type 2 diabetes, erectile dysfunction and infertility presents to Endocrine clinic after initial evaluation by Urology revealed elevated prolactin. He reported headaches, gynecomastia associated with liquid discharge from nipples, and minor issues with peripheral vision. He was started empirically on cabergoline for probable prolactinoma and within 48 hours developed worsening frontal headache, cough and clear fluid leakage from his right nostril. Labs revealed prolactin over 2600 ng/ml. MRI pituitary showed evidence of pituitary adenoma as well as likely CSF leak. Cabergoline was stopped and the patient was sent to the emergency room. The patient was underwent urgent neurosurgical transsphenoidal endoscopic surgery and CSF leak repair with resolution of rhinorrhea and cough. Post-operative MRI was consistent with minimal residual tumor. He was monitored in the NICU with no obvious post-operative pituitary hormone imbalance, diabetes insipidus, adrenal insufficiency or syndrome of inappropriate ADH. Months after discharge, the patient’s prolactin remained elevated to the 600’s ng/ml and repeat MRI showed a mass occupying the entire sella and suprasellar cistern, compressing the optic chiasm. Conclusion: In this case of a patient with the subtype of aggressive prolactinoma, there seems to be a more rapid presentation of complications. When treating these rare subtypes, physicians need to stay vigilant of developing complications or even consider nonstandard therapies as first-line management. 1. Molitch ME, Drummond J, Korbonits M. Prolactinoma Management. In: Feingold KR, Anawalt B, Boyce A, et al., eds. Endotext. South Dartmouth (MA): MDText.com, Inc.; January 6, 2022.2. Lasolle H, Ilie MD, Raverot G. Aggressive prolactinomas: how to manage?. Pituitary. 2020;23(1):70-77. doi:10.1007/s11102-019-01000-73. Arimappamagan A, Sadashiva N, Kandregula S, Shukla D, Somanna S. CSF Rhinorrhea Following Medical Treatment for Prolactinoma: Management and Challenges. J Neurol Surg B Skull Base. 2019;80(6):620-625. doi:10.1055/s-0039-1677686 Presentation: Friday, June 16, 2023