Salivary duct carcinoma arising in IgG4-related autoimmune disease of the parotid gland.
Hyper IgG4 disease or IgG4-related sclerosing/autoimmune disease is a multisystem condition characterized histologically by fibrosis, lymphoplasmacytic infiltration, and abundant IgG4 plasma cells associated with raised serum IgG4 levels. We present a case of salivary duct carcinoma of the parotid gland in a background of chronic sclerosing sialadenitis that also involved the submandibular gland with associated regional lymphadenopathy. The serology showed raised total IgG levels of 16.3 g/L (reference range, 6.0-15.0) and raised IgG4 levels of 3.41 g/L (reference range, 0.07-1.70). The salivary duct carcinoma contained areas of dense fibrosis and abundant IgG4-positive plasma cells (>100 per high-power field [hpf]). The adjacent noncarcinomatous areas, submandibular gland, and regional lymph nodes also contained plasma cells immunoreactive to IgG4 with densities higher than 100/hpf. To the best of our knowledge, this case is the first documentation of malignancy occurring in a background of IgG4-related autoimmune disease of the salivary gland.
Gill
Jespal
J
Diagnostic Medlab, Auckland, New Zealand. jespal_gill@hotmail.com
Angelo
Neville
N
Yeong
Mee Ling
ML
McIvor
Nick
N
D000368:Aged; D001327:Autoimmune Diseases / Q000150:complications / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D010306:Parotid Gland / Q000473:pathology*; D012468:Salivary Gland Neoplasms / Q000097:blood / Q000209:etiology / Q000473:pathology*; D012598:Sclerosis; D012793:Sialadenitis / Q000097:blood / Q000150:complications / Q000276:immunology / Q000473:pathology*
D007074:Immunoglobulin G