An unusual case of recurrent autoimmune hypophysitis.

Autoimmune hypophysitis (AH) is an inflammatory disease that can present either as empty sella or as pituitary mass. A 16-years-old girl was admitted at our Unit for primary amenorrhea. A pituitary MRI performed 2 years before for severe headache demonstrated a large sellar and suprasellar lesion. As a craniopharyngioma was suspected, the consultant neurosurgeon suggested the removal of the lesion. Two months later, a preoperative MRI showed the disappearance of the lesion and a residual empty sella, figure consistent with AH. When the patient came at our observation, basal and dynamic testing documented a state of hypopituitarism, high titers of antipituitary antibodies and a partial empty sella at MRI. Hormonal replacement therapy was started, obtaining a good clinical and biochemical control. Four years later, severe headache and a MRI suggestive of pituitary adenoma recurred. A relapse of the autoimmune phenomenon seemed the most feasible hypothesis. A MRI performed 3 months later did not show any pituitary lesion and empty sella was again described. This patient represents one of the few reported cases of recurrent hypophysitis and demonstrates that both pituitary enlargement and empty-sella can be seen in the same patient at different times of his history.