ODP352 Steroid-sparing immunosuppressive therapy controls refractory headaches due to lymphocytic hypophysitis: a case report

Background Systemic glucocorticoid therapy has been used to control headaches associated with lymphocytic hypophysitis (LH), a rare autoimmune inflammation of the pituitary gland and stalk. Steroid-sparing immunosuppressive therapies, like mycophenolate mofetil (MM), have proven to be effective for patients with many systemic inflammatory and rheumatological conditions. However, the safety and efficacy of steroid-sparing immunosuppressive therapies for LH has not been studied. Clinical Case Here we report a case of a 31-year-old male who presented with worsening headache, fatigue, polyuria, insomnia, low libido, and decreased appetite. His laboratory results were consistent with central diabetes insipidus (DI), central hypothyroidism, central adrenal insufficiency, and hypogonadotropic hypogonadism without evidence of growth hormone deficiency. Initial pituitary MRI revealed pituitary enlargement and thickening of the stalk. He was started on desmopressin, levothyroxine, testosterone cypionate, and physiologic glucocorticoid replacement with prednisone 5mg daily. He continued to endorse incapacitating occipital headaches not relieved by ibuprofen, topiramate, gabapentin, amitriptyline, sumatriptan, or rizatriptan, and only temporary relieved by occipital nerve blocks. A pituitary biopsy confirmed the diagnosis of LH. Given his persistent, debilitating headaches, prednisone was increased to supraphysiologic doses. Headaches resolved on prednisone 40mg daily but recurred two months after tapering down to prednisone 5mg daily. Pituitary MRI after 4 months revealed a mild interval increase in enhancement and thickening of the pituitary stalk. Prednisone was increased to 20mg daily, and he was started on MM for progressive inflammation. Prednisone was tapered down to 5mg daily over the course of 3 months as MM dose was increased to 1000mg twice a day. Headaches completely resolved. After 4 months of MM therapy, pituitary MRI showed decrease in size of pituitary stalk thickening and pituitary, consistent with treatment effect. After 6 months of MM therapy, MRI brain showed further decrease in pituitary size and resolution of pituitary stalk thickening. He did not experience any adverse effect on MM. Serial complete blood counts, liver function tests, and basic metabolic panels were normal. Two years after diagnosis and one year on MM therapy, his DI resolved, his adrenal insufficiency was well managed with prednisone 4mg daily, he was euthyroid on levothyroxine 75mcg daily, and his hypogonadism was treated adequately with testosterone cypionate 50mg weekly with improved libido and energy. Conclusion MM was effective in treating intractable headaches caused by biopsy-proven LH. Radiologic signs of improvement in pituitary inflammation coincided with patient's report of headache relief and initiation of MM, without concurrent use of supraphysiologic glucocorticoids. Treatment was well-tolerated with no reported adverse effect. Steroid-sparing immunosuppressive therapy like MM may be considered as a therapy for LH, particularly in patients who depend on prolonged courses of supraphysiologic glucocorticoid treatment to alleviate symptoms. Presentation: No date and time listed