A case of IgG4-related anterior mediastinal sclerosing disease coexisting with autoimmune pancreatitis

• DOI: 10.1186/s40792-020-00939-1
• Publication Date: 2020-07-23T11:04:10Z
• Authors: Hiroshi Matsui; Takahiro Utsumi; Natsumi Maru; Yohei Taniguchi; Tomohito Saito; Haruaki Hino; Mitsuaki Ishida; Koji Tsuta; Tomohiro Murakawa
• Keywords: IgG4-Related Disease; Autoimmune Pancreatitis

Abstract Background IgG4-related disease (IgG4-RD) is a systemic fibro-inflammatory condition that predominantly involves exocrine organs. Concerning its thoracic presentation, it often manifests as interstitial lung or fibrosing mediastinitis. It very rare for IgG4-RD to form well-defined mass in the anterior mediastinum, mimicking an encapsulated thymoma. Case presentation An 82-year-old man with autoimmune pancreatitis under treatment oral corticosteroids was found have peripancreatic lymphadenopathy on computed tomography. Subsequent positron emission tomography revealed abnormal uptake (maximal value 3.6) by thymic well lymph nodes. Exacerbation of suspected, and we increased steroid dosage. As result, nodes, mediastinal mass, decreased size. The suspected be thymoma because lobulated shape, degree fluorodeoxyglucose accumulation, response steroids, patient referred our department. serum anti-acetylcholine receptor antibody test negative. A thoracoscopic tumor resection performed diagnostic therapy. Histopathological analysis dense lymphoplasmacytic infiltration sclerotic stroma within tumor. Immunohistochemical abundant IgG4-positive plasma cell infiltrates over 50% IgG4/IgG-positive cells. We did not see either keratin-positive thymocytes terminal deoxynucleotidyl transferase-positive lymphocytes. Furthermore, deviation kappa chain lambda chain-positive cells noted. Accordingly, sclerosing diagnosed. Conclusions masses mediastinum are rare, effect prognosis remains unclear. had potentially been categorized Castleman’s disease.