IgG4 相關性疾病是一個全身性發炎纖維化的疾病，最近十年才獲得廣泛的重視與了解， 且幾乎在身體每個器官組織都可能發現。此疾病的特徵為腫瘤樣的病灶、IgG4 陽性淋巴漿細 胞浸潤 (lymphoplasmacytic infiltration) 及席紋樣纖維化(storiform fibrosis)，血清中IgG4 濃度 常有升高現象。此疾病的診斷主要經由病理組織切片及免疫化學染色來確認，其中淋巴漿細 胞浸潤、席紋樣纖維化、及閉塞性靜脈炎(obliterative phlebitis) 是病理診斷的典型特徵。IgG4 相關性疾病的治療包括類固醇、免疫抑制劑及B 細胞清除療法 (B-cell depletion therapy)。本 文藉由回顧最新文獻，使臨床醫師對IgG4 相關性疾病有深入的了解，並在疾病初期予以診斷 及治療，避免此疾病產生器官損壞、嚴重纖維化甚至死亡。

IgG4-related disease (IgG4-RD) is a newly recognized fibroinflammatory disease involving essentially any organ. The disease is characterized by tumefactive lesions, a dense lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells, storiform fibrosis, and often (but not always) elevated serum concentrations of IgG4. The diagnosis is based upon histopathological and immunohistochemical assessment. The lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis are three major pathology features of IgG4-RD. Treatment options include corticosteroids, immunosuppressive drugs, and B-cell depletion therapy. Clinicians should be aware of the disease and ensure early diagnosis and therapy, which can stop organ damage, disabling tissue fibrosis, and death.