Secondary hypophysitis causes are variable and consist of local pituitary lesions (adenomas, craniopharyngiomas, Rathke's cleft cysts, germinomas and meningiomas), systemic inflammatory diseases (sarcoidosis, granulomatosis with polyangiitis, vasculitis), infectious diseases (tuberculosis, syphilis, aspergillosis, coccidioidomycosis), infiltrative diseases (hemochromatosis, amyloidosis, Langerhans cell histiocytosis) and secondary to treatment (anti-CTLA-4 monoclonal antibodies, interferon-alfa), but the source is frequently unknown. Here, CTLA4 is linked to central nervous system cyst.