[en] A 40-yr-old female presented with an extensive lesion of the sellar area and the sphenoid sinus, spreading to the optic nerves and associated with pachymeningitis. Histological findings were consistent with an inflammatory pseudotumor, and steroid treatment allowed the disappearance of all the lesions. Inflammatory pseudotumors of the pituitary are very rare. This case appears unique with regard to the extension of the lesions and the dramatic response to medical treatment. The differential diagnosis of inflammatory lesions of the pituitary is difficult. It relies mainly on histological analysis and includes sarcoidosis, Wegener's granulomatosis, histiocytosis (Langerhans, Rosai-Dorfman, and Erdheim-Chester diseases) and lymphocytic hypophysitis.