title: IgG4-related lacrimal sac diverticulitis.
abstract: IgG4-related disease is characterized by elevated serum IgG4 and tissue infiltration by IgG4-positive plasma cells. We herein report a case of lacrimal sac diverticulitis with marked IgG4-positive plasma cell infiltration. An 89-year-old woman presenting with right lower eyelid mass. Imaging modalities demonstrated a cystic orbital mass located beneath the globe and adjacent to enlarged lacrimal sac. Serological tests showed high IgG4 and normal IgG levels, measuring 242 and 1603 mg/dl, respectively. The orbital mass was surgically excised. Histologically, the excised tissue demonstrated marked inflammation with fibrosis surrounded by mononuclear epithelial cells. A variety of IgG and IgG4-positive plasma cells infiltrated the stroma. This patient was diagnosed as an IgG4-related lacrimal sac diverticulitis, based on current diagnostic criteria of IgG4-related disease. It is likely that IgG4-related inflammation occurs in a lacrimal sac diverticulum, which should be considered a differential diagnosis in inferior orbital tumors.
authors.affiliation: Department of Ophthalmology, Teine Keijinkai Hospital , Maeda 1-12, Teine-ku, Sapporo , Japan .
authors.forename: Satoru
authors.initials: S
authors.lastname: Kase
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Toshiya
authors.initials: T
authors.lastname: Shinohara
authors.forename: Manabu
authors.initials: M
authors.lastname: Kase
mesh_terms: D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D004238:Diverticulitis / Q000097:blood / Q000473:pathology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007766:Lacrimal Apparatus Diseases / Q000097:blood / Q000473:pathology*; D010950:Plasma Cells / Q000473:pathology*
chemical_list: D007074:Immunoglobulin G