Figure 1: (A-F) Sclerosing dacryoadenitis form of IgG4RD. (A): Lacrimal gland biopsy, 2x Hematoxylin & Eosin (HE) stain showing areas of fibrosis (arrow) and dense lymphoplasmacytic infitrate (asterix). (B): HE stain, 20x. Storiform fibrosis (arrow) characterized by thick eosinophilic collagen bands with a whorl-like appearance. (C): HE stain 20x. Dense lymphoplasmacytic infiltrate. (D & E): CD138 and IgG4 immunohistochemistry (Peroxidase, 20x) showing increased tissue IgG4 CD138 positive plasma cells ~134 cell/ hpf. (E & F): IgG4 and IgG immunohistochemistry (Peroxidase, 20x) showing increased IgG4: IgG ratio (90%).