FRI312 Diplopia And Headache After Treatment With GnRH Agonist

Disclosure: A.A. Zakkar: None. M. Al Mushref: None. M. Fadanelli: None. Case Report: The Patient is a 46-year-old male with past medical history of hypertension and prostate cancer, currently undergoing treatment with leuprolide acetate injections, who presented to the emergency department with a complaint of worsening headache. He received his second injection 3 days prior to admission and within hours he developed a headache in the frontal area that was continuous and worsening over time, increasing with positional changes of his head. One day after the treatment he developed persistent double vision. The patient reported that he has had worsening vision over the last year and was to see an ophthalmologist but was diagnosed with prostate cancer at the same time so he became more focused on the oncologic care. He also reported poor balance, excessive thirst and increased urination of large volumes of urine every hour with nocturia several times. On exam the vital signs were normal, he was A&Ox4 and in no distress. He had left abducens and oculomotor nerve palsy but an otherwise benign exam. MRI of the brain revealed a sellar mass measuring 2.2 x 1.7 x 2.3 cm consistent with pituitary macroadenoma extending into the suprasellar cistern, compressing the pituitary stalk and the optic chiasm. Patient was evaluated by ophthalmology who noted +2 optic nerve edema of the left eye. Laboratory evaluation revealed low ACTH of 6 pg/mL at 5:30AM along with corresponding cortisol level of only 1.6 mcg/dL. FSH was low and LH undetectable as expected with GnRH agonist therapy. Growth hormone level, IGF-1, l and prolactin levels were all normal. The TSH was 0.50 microunits/mL with a freeT4 of 1.0. Urinalysis revealed dilute urine with specific gravity <1.006. Serum sodium on admission was 137 mmol/L and after overnight fasting was 140 mmol/L. The patient was started on desmopressin 0.1 mg po at bedtime and on intravenous dexamethasone 4 mg q6hrs. He was evaluated by neurosurgery and ENT who recommended trans-sphenoidal resection of the mass. Pathology report of the specimen was consistent with a pituitary adenoma with infarction without hemorrhage. The patient reported an improvement in his left eye vision and lateral rectus palsy. He was transitioned to oral hydrocortisone 20 mg daily and 10 mg every afternoon prior to discharge. On follow up with endocrinology several months later he was found to have persistent adrenal insufficiency and developed central hypothyroidism that required treatment. Conclusion: Patients with an undiagnosed pituitary adenoma are at risk of tumor expansion and mass effect as well as pituitary apoplexy during treatment with GnRH agonists. In our case clinical presentation was consistent with pituitary apoplexy without evidence of pituitary hemorrhage soon after GnRH agonist. A full ophthalmologic exam may be an appropriate screening prior to initiation of such therapy. Presentation: Friday, June 16, 2023