MON-119 Lymphocytic Hypophysitis in an Adolescent Female: Diagnostic Challenges and Therapeutic Response

Abstract Disclosure: H.C. Davuluri: None. K. Kaur: None. P. Chaulagain: None. E.I. Krug: None. A 16-year-old female presented with a history of headaches of 1 year duration and was initially diagnosed with migraine without aura. At the same time, she developed menstrual irregularity and eventual amenorrhea, was prescribed a 3 months course of OCPs. Amenorrhea persisted following discontinuation of OCP regimen. She was seen by a pediatric neurologist for worsening headaches, associated with light sensitivity and worsening of pain with noise, coughing or sneezing. Brain MRI revealed a 1.5 cm pituitary mass with displacement of the optic chiasm. Fortunately, ophthalmologic evaluation was unremarkable. Endocrine evaluation revealed evidence of central hypogonadism and mild hyperprolactinemia with prolactin level of 57.6 ng/ml [4.8-33.4 ng/ml]. ACTH, cortisol, growth hormone, IGF-I, TSH, free T4 levels were within normal limits. Her growth and development were normal for her age. Cabergoline (0.5 mg twice weekly) was started, reducing prolactin to 0.2 ng/ml, with no significant change in headache frequency and no resolution of amenorrhea. Subsequently, she underwent transnasal transsphenoidal biopsy of the suspected pituitary mass. Intraoperative findings revealed a thickened dura with fibrous appearance and a mass-like lesion adherent to the dura. Frozen sections analysis revealed no evidence of a neoplasm; the findings are suggestive of lymphocytic hypophysitis. Histopathology confirmed the diagnosis of lymphocytic hypophysitis. Further underwent a rheumatological workup, including ESR, CRP, ANA, anti-SSA/SSB, anti-dsDNA, and ANCA, all of which were unremarkable. She received glucocorticoid therapy with prednisone, 25 mg daily with prolonged steroid taper over a period of 12 months. Serial brain MRIs revealed a reduction in the size of the pituitary gland to 6 mm after 4 months of treatment. Repeat imaging at 3 and 6, 9 and 12 months showed continued resolution. Her menstrual cycle normalized after 4 months of treatment, and headaches significantly improved. Glucocorticoid therapy has been discontinued after 12 months of treatment with no evidence of recurrence so far. Discussion: We present a case of histologically confirmed lymphocytic hypophysitis with complete radiologic and functional recovery following prolonged glucocorticoid therapy at a relatively low dose with very slow taper. Affected patients typically present with severe headaches and symptoms of pituitary dysfunction. Optimal treatment is not known at this time. There is a report describing clinical improvement in 4 patients following high dose methylprednisolone pulse therapy and another report describing resolution of symptoms after a short course of glucocorticoids in 2 patients. Additional research is needed to determine best treatment strategy, but it appears that high index of suspicion and early diagnosis may prevent progressive pituitary atrophy and hypopituitarism. Presentation: Monday, July 14, 2025