8264 An Interesting Case of Hypophysitis in a Young Woman

Abstract Disclosure: A. Garcia: None. R. Sharma: None. C.M. Knight: None. Background Hypophysitis is an uncommon disorder and presents with clinical signs and symptoms along with biochemical abnormalities. Herein, we present a case of hypophysitis that responded well to high dose steroids. Case An 18 y.o black, adopted woman presented to hospital with complaints of headache and vision disturbances. Endocrinology was consulted for pituitary macroadenoma. Symptoms started a month prior. She had extensive work-up at an outside hospital including brain imaging, CSF analysis, and bloodwork. No definitive diagnosis was made and she was sent home on topiramate. Her symptoms continued to worsen prompting her to seek another opinion. No family history as she is adopted. She has a history of depression controlled with medication. MRI Brain showed 1.8x1.1x1.6 cm T2-enhancing mass with suprasellar extension deforming the midline optic chiasm. Initially, a diagnosis of macroadenoma was made and Endocrinology and Neurosurgery services consulted. Patient denied galactorrhea, menstrual abnormality, polyuria, polydipsia, cold intolerance, orthostasis, or weight gain. Bloodwork was significant for low TSH (0.045 uIU/ml; normal 0.35-4.94), low free T4 (0.58 ng/dl; normal 0.76-1.79). Thyroid functions were normal approximately one year prior. Cortisol was very low at 1.8 mcg/dL and ACTH inappropriately low-normal at 12 pg/ml (normal 6-50). LH and estradiol were low, while FSH was low normal. Prolactin, GH, IGF-1, sodium, glucose and creatinine were normal. Endocrine reviewed the previous MRI brain done four weeks ago that was reported as normal. Discussion with previous outside hospital radiologist suggested that pituitary was indeed not normal but was fuller with convexity towards chiasm although no definitive adenoma was found. Since it is unlikely that such adenoma would develop over 4 weeks, Endocrinology reached out to our radiologist who assessed this as pituitary enlargement due to likely hypophysitis, especially when compared to imaging 4 weeks ago. Further work up showed mildly-elevated ESR, and normal ACE, dsDNA, ANA, and Sjogren’s antibody levels. Tests for pregnancy, Lyme disease, tuberculosis, EBV and syphilis were negative. SARS-CoV-2 was negative for COVID. IgG4 levels were normal. CSF analysis was normal. She was started on levothyroxine and high-dose corticosteroids with improvement in her symptoms. Repeat imaging after 5 days of corticosteroids showed about 30% decrease in pituitary size. A diagnosis of likely lymphocytic hypophysitis was made and pituitary surgery averted for time being. Conclusion We present a case of possible lymphocytic hypophysitis in a young woman who avoided pituitary surgery due to diligent history and examination, in addition to a multidisciplinary team approach. It is very important to have prompt multidisciplinary approach if there is any doubt about a diagnosis as in this case. Presentation: 6/3/2024