Background: Primary hypophysitis (PH) is a rare disease that represents a challenge among differential diagnosis and management. Our aim was to describe clinical characteristics, diagnostic criteria and different treatment outcomes in patients with PH. Multicentric, retrospective study. Clinical presentation, endocrine function, magnetic resonance imaging findings, visual field defects at diagnosis and treatment outcomes were recorded.

Methods: Twenty-eight patients (23 women), with PH were included. Median age: 37.

Results: The most frequent symptoms: headache: 68%, polyuria-polydipsia: 50% and visual disturbances: 48%. At diagnosis, anterior pituitary deficiency was present in 71%, being hypogonadotrophic hypogonadism the most frequent manifestation. The radiological findings: symmetric lesion: 78.5%, homogeneous enhancement: 78.5% and pituitary stalk thickening: 70%. Association with pregnancy or puerperium was found in 4/23 women (17%). Fourteen patients did not receive any treatment ("wait and see" group), 8 underwent surgery for mass reduction or resection and 6 were treated with immunosuppression therapy. Among 15 patients with histopathological diagnosis, 9 were lymphocytic hypophysitis, 5 IgG4 related hypophysitis and 1 xanthomatous hypophysitis. Thirteen were diagnosed by established clinical criteria. Mass reduction was observed in 43% of "wait and see group" patients, 62.5% of operated patients and 50% with immunosuppression therapy. Compressive symptoms showed improvement in the 3 groups, with modest effect on anterior pituitary function, diabetes insipidus did not resolve in any patients.

Conclusions: In patients without severe compressive symptoms, we adopted a "wait and see" approach. In patients with uncertain diagnosis of PH or severe compressive symptoms, transsphenoidal surgery was the best option.