THU053 Partial Third Nerve Palsy As A Presentation Of Prolactinoma, A Case Report

Disclosure: M. Ahmad: None. I. Iqbal: None. M. Khan: None. A. Estepa: None. U. Siddiqui: None. Introduction: Prolactinomas in men are often found when they are quite advanced, large and cause compression of surrounding structures. This compression causes patients to present with symptoms of hypogonadism, headaches, and vision changes. Uncommonly, pituitary adenomas have been shown to cause vision changes associated with third nerve palsy. We describe the case of a 21-year-old male presenting with vision changes and headaches who was found to have a large prolactinoma causing partial third nerve palsy. Case description: A 21-year-old male with no significant past medical history presented to the emergency department (ED)after being sent from his primary care provider’s office for headaches. The patient had been suffering from left sided headaches and blurry vision for the past two months. On physical examination the patient was normotensive (128/61 mmHg), afebrile (37.3 degrees Celsius) with a normal respiratory rate and heart rate (18 breaths per minute and 73 beats per minute respectively). He was noted to have left eyelidptosis with his left pupil being slightly more dilated than his right pupil at 5 mm and was slowly reactive. The patient’s blood work was significant for the following: sodium 141 mmol/L, potassium 4.4 mmol/L,bicarbonate 24 mmol/L, hemoglobin 13.4 g/dL, TSH 2.21 uIU/mL, free T4 0.9 ng/dL, prolactin >4700ng/mL, adrenocorticotrophin hormone <9 pg/ml, cortisol 0.9 mcg/dL, follicle-stimulating hormone 2.5uIU/ml, luteinizing hormone 4.7 uIU/ml, free testosterone 3.4 pg/ml, and total testosterone 19 ng/dL. The patient underwent brain imaging with his CT angiogram demonstrating a large sellar mass extending superiorly, causing displacement of the internal carotid artery. An MRI of the brain described the mass to be 3.4 x 2.7 cm in dimensions. The patient was first started on dexamethasone 4 mg intravenously every 6hours, tapered over a week, along with once weekly cabergoline which was eventually titrated up to 1 mg weekly. The patient had rapid clinical improvement with his symptoms resolving in four days, and was eventually discharged. He now follows with endocrinology as an outpatient. Discussion: Prolactinomas can present with a wide range of symptoms in men including headache, infertility, decreased libido and vision changes. Rarely, prolactinomas have been associated with third nerve palsy with proposed mechanisms including compression of the nerve in the cavernous sinus or compression of the nerve’s vascular supply. Through this case we hope to highlight this uncommon presentation of prolactinoma and propose it be considered in the workup for third nerve palsy. Presentation: Thursday, June 15, 2023