Photomicrographs of Case 3. (a, b) High-power photomicrographs showing inflammatory cells infiltrating the pituitary tissue (a), which appeared to be chronic inflammatory lesions with prominent histiocytes and corresponded to nonspecific granulomatous inflammation, not epithelioid granuloma as seen in sarcoidosis, and the extradural tissue (b). Hematoxylin and eosin staining, original magnification × 200. (c) Immunohistochemical staining showing infiltrated plasmacytes positive for IgG4 in the pituitary tissue. Original magnification × 200.