PDCD1 and Langerhans cell histiocytosis: Secondary hypophysitis results from systemic or local conditions, including Sjögren’s syndrome, systemic lupus erythematosus, sarcoidosis, Langerhans cell histiocytosis, and IgG4-related disease; it also includes drug-induced forms (e.g., immune checkpoint inhibitors targeting CTLA4 or PDCD1/PDCDL1, daclizumab) and rare post-vaccination cases (including reports linked to SARS-CoV-2 infection or vaccination) [25].