MON-118 Outcomes of Primary Hypophysitis: A Single Center Experience

Abstract Disclosure: H.M. Klatte: None. G.E. Vates: None. I. Shafiq: None. Purpose: Primary hypophysitis is a rare auto-immune disorder of the pituitary gland, often leading to varying degree of clinical presentation and outcomes. Histologically, the different subtypes include lymphocytic, granulomatous, IGg4, and xanthomatous hypophysitis. This study aims to describe the clinical presentation, diagnosis treatment, and outcomes from the last 15 years at our Pituitary Clinic. Methods: A retrospective study from the years 2010-2025 was conducted on patients with biopsy confirmed primary hypophysitis seen at Pituitary Clinic at University of Rochester. Data about symptom presentation, diagnostic evaluation, hormonal labs, temporal progression, and treatment outcomes was collected from patients. Outcomes: Eight patients (five female, three male) were diagnosed with primary hypophysitis. Six were diagnosed with lymphocytic hypophysitis, one with IgG4 hypophysitis, and one diagnosed with mixed IgG4 and lymphocytic hypophysitis. Two of the five female patients develop symptoms within one year of pregnancy. The mean age at diagnosis was 39 years, with five patients younger than 35, one between 35-50 years old, and two older than 50 years. The most common presenting symptoms was polydipsia/polyuria (75%), followed by headaches (37%), vision changes (37%), dizziness/nausea (37%) and fatigue (37%). MRI head typically showed pituitary enlargement with thickened infundibulum except in two patients MRI head showed pituitary macroadenoma. Biochemical work up confirmed arginine vasopressin deficiency (75%), central hypothyroidism (75%), central adrenal insufficiency (62%), hypogonadism (37%), and GH deficiency (25%). All patients had biopsy proven hypophysitis diagnosis. Most patients received high dose glucocorticoids as the main form of treatment. One patient required numerous debulking surgeries, radiation treatment for symptomatic relief, while another needed high dose corticosteroid and radiation treatment. Both patients requiring multiple intervention were older than 55 years. Only two patients, both with history of pregnancy, experienced complete remission of the disease requiring no medications. The rest of the patient remined on hormonal replacement from beginning or with time develop hormonal deficiency. Conclusions: Hypophysitis is a rare autoimmune disorder of the pituitary gland with variable clinical presentation and course, often requiring long-term hormone replacement. Glucocorticoid therapy is the primary treatment for patient with visual compromise. In our case series, we observed that both pregnancy history and age influence clinical outcome. Spontaneous remission was more common in postpartum patients, while older patients requiring additional interventions, highlighting a potential distinct disease course in these subgroups. Presentation: Monday, July 14, 2025