[Ipilimumab, a cause of autoimmune hypophysitis].

Hypophysitis represents a heterogeneous group of inflammatory lesions affecting the pituitary gland with a complex pathogenesis and is insufficiently characterized. The different types belong to the group of non-hormone secreting sellar masses, with which they share clinical, and sometimes also radiographic, presentation. These similarities make differential diagnosis difficult in the absence of surgery, which is not indicated in hypophysitis but allows for pathological study. The clinical signs of hypophysitis are similar to those of other sellar masses and include headache, visual disturbances, and variable degrees of hypopituitarism and diabetes insipidus. Hypophysitis may be classified based on various criteria. Adenohypophysitis, infundibuloneurohypophysitis, and panhypophysitis are distinguished based on the anatomical location of the condition. There may be lymphocytic, granulomatous, xanthomatous, and mixed hypophysitis depending on the histopathological characteristics. Based on etiology, a distinction between primary hypophysitis, either isolated or as part of a systemic disease; hypophysitis secondary to sellar diseases such as germinoma, Rathke cyst, craniopharyngioma, or pituitary adenoma, or occurring in the setting of systemic diseases such as Wegener’s granulomatosis, tuberculosis, sarcoidosis, and syphilis; finally, hypophysitis secondary to immunomodulatory drugs such as interferon and antibodies to cytotoxic T-lymphocyte antigen-4 (CTLA-4) has been reported. In the context of the use of immunomodulatory therapies, we report three cases of autoimmune hypophysitis secondary to ipilimumab occurring during the treatment of metastatic melanoma. Thirteen patients with metastatic melanoma have been treated to date with ipilimumab at our hospital. Table 1 summarizes the clinical and laboratory data. Case 1: A 41-year-old male with stage IV melanoma and hepatic and nodal metastases. After the third dose