Endocrine Abstracts

Introduction: Hypophysitis, an infrequent inflammatory condition of the pituitary gland, is typically managed with glucocorticoids, reserving surgery for significant mass effects and considering immunosuppressants or radiotherapy for refractory cases. Recent reports indicate positive outcomes with immunosuppressants. Here, we present a case of recurrent xanthogranulomatous hypophysitis in a 16-year-old female successfully treated with Rituximab.

Case Report: A 16-year-old female with no pertinent medical history presented to our emergency department with a severe frontal headache, diplopia, nausea, amenorrhea, polyuria, and polydipsia persisting for 4 months. Physical examination revealed a mild afferent pupillary defect along with complete six-nerve and partial third-nerve palsies. MRI indicated a solid selar mass with a central cystic area, intense peripheral contrast enhancement, and pituitary stalk infiltration displaying intense and homogeneous contrast enhancement. Blood tests revealed deficiencies in corticotroph, gonadotroph, and thyrotroph axis, along with arginine vasopressin deficiency. Somatotroph axis and prolactin levels remained unaffected. Additional tests showed positive antithyroid antibodies, with negative alpha-fetoprotein and Beta-HCG in both serum and cerebrospinal fluid. The patient received high-dose glucocorticoid therapy, leading to significant clinical and radiological improvement. However, after corticosteroid tapering, a relapse occurred, requiring transsphenoidal surgery. Pathological analysis revealed chronic inflammation with predominantly CD20-positive B-cell infiltration, consistent with xanthogranulomatous hypophysitis. Following surgery, a relapse occurred, prompting the use of Rituximab, a monoclonal antibody targeting CD20-positive B cells. The patient received two doses of 1000 mg IV four weeks apart, followed by a single dose of 750 mg IV every 6 months. After four doses, the patient successfully discontinued corticosteroid therapy, experiencing sustained disease remission and excellent symptomatic control.

Conclusion: Rituximab emerges as an effective and sustainable treatment for hypophysitis, providing a valuable alternative to prolonged corticosteroid therapy or surgery.