Endocrine Abstracts

JOINT1746

Background: Hypophysitis is a rare inflammatory disease of the pituitary gland that can closely mimic neoplastic tumors such as histiocytosis or germinoma. In pediatric patients, it’s challenging to distinguish between these conditions because of their overlapping clinical, endocrinological, and radiological features.

Case Presentation: We report the case of a 5-year-old child who initially presented with polyuria, and polydipsia. A hormonal evaluation confirmed central diabetes insipidus, and the patient was started on desmopressin therapy. Brain magnetic resonance imaging (MRI) revealed an enlarged of pituitary gland and thickened stalk, Tumor markers commonly associated with germinoma, including beta-human chorionic gonadotropin (β-hCG) and alpha-fetoprotein (AFP), were negative. Autoimmune evaluation was negative. The patient was started on oral steroid therapy at a dose of 1 mg/kg per day for one month. The initial response was significant, with regression of pituitary stalk thickening on follow-up MRI. However, new anterior pituitary deficiencies (GH, TSH, and ACTH deficiencies) developed. A Follow-up MRIs showed a progressive disappearance of pituitary stalk thickening, while the pituitary gland became hypoplastic. Considering the persistent endocrine abnormalities and the possibility of an underlying neoplastic process, Regular clinical monitoring was maintained through serial imaging and endocrine evaluations.

Conclusion: Autoimmune (lymphocytic) hypophysitis is a rare disease that should be considered in the differential diagnosis of any nonsecreting pituitary mass. An accurate diagnosis is crucial in guiding appropriate treatment and preventing long-term complications.