Rare case of primary granulomatous hypophysitis mimicking pituitary macroadenoma: A diagnostic challenge

ABSTRACT: Granulomatous hypophysitis is a rare form of pituitary inflammation that closely mimics pituitary macroadenoma in clinical presentation as well as radiological appearance. Histopathology remains the gold standard diagnostic modality. Here, we present the case of a young female who presented with symptoms of anterior and posterior pituitary dysfunction, including secondary amenorrhea, cold intolerance, polyuria, and polydipsia. Magnetic resonance imaging revealed a sellar mass with suprasellar extension, suggesting a pituitary macroadenoma. Histopathological examination of the transsphenoidal biopsy revealed granulomatous hypophysitis. Extensive systemic workup of the patient did not identify any secondary infectious or autoimmune etiological conditions. She was treated with corticosteroids, thyroxine, and desmopressin. This case emphasizes the importance of considering hypophysitis as a differential diagnosis of common sellar lesions like pituitary macroadenoma and highlights the role of histopathological examination in definitive diagnosis and to determine the appropriate course of management.