Hypophysitis is a rare pathology. As clinical symptoms and radiologic signs are non-specific, the diagnostic is difficult. Hypophysitis's pathogenesis remains obscure but new histological and etiological variants have recently been reported. Primary hypophysitis is the main form. For the first time, hypophysitis in ANCA-associated vasculitides has been reported. An entity of immunoglobulin G4 related plasmatic hypophysitis has been described and well-defined diagnostic criteria are proven. Monoclonal antibodies directed against the cytotoxic T-lymphocyte antigen-4 (CTLA-4), investigated in metastatic cancer, can induce hypophysitis. Hypophysitis's pathogenesis remains obscure but several candidate pituitary autoantigens have been described in the last decade, although none has proven useful as a diagnostic tool.