Histopathology Section, Institute of Liver Studies, King's College Hospital, Denmark Hill, London, UK.
Semin Diagn Pathol. 2012 Nov;29(4):205-11. doi: 10.1053/j.semdp.2012.07.005.
Since immunoglobulin G4 (IgG4)-related sclerosing cholangitis was first described in 2004, this condition has been recognized as a distinct entity characterized by unique pathologic features. Affected bile ducts show diffuse wall thickening, which represents transmural sclerosing inflammation composed of a dense lymphoplasmacytic infiltrate and fibrosis arranged at least focally in a storiform pattern. A diffuse IgG4-positive plasma cell infiltrate is demonstrable by immunohistochemistry. More than 90% of patients with IgG4-related sclerosing cholangitis have type 1 autoimmune pancreatitis, the remaining presenting as isolated cholangitis. The diagnosis requires a multidisciplinary approach, in which pathologic examination has a critical role. Tissue diagnosis on biopsy specimens (ie, bile duct biopsy, liver needle biopsies) is important, particularly for patients with isolated cholangitis, given the fact that radiological findings of IgG4-cholangitis are not reliable enough for establishing the diagnosis. Furthermore, serum IgG4 levels can be, albeit mildly, elevated in other biliary disorders. Histologic mimics of IgG4-related sclerosing cholangitis include primary sclerosing cholangitis, follicular cholangitis, and sclerosing cholangitis with granulocytic epithelial lesion, the latter 2 being recently described entities.
自 2004 年首次描述 IgG4 相关硬化性胆管炎以来，该病已被认为是一种具有独特病理特征的独特实体。受影响的胆管显示弥漫性管壁增厚，代表由致密的淋巴浆细胞浸润和纤维化组成的壁层间硬化性炎症，至少局灶性呈席纹状排列。免疫组织化学显示弥漫性 IgG4 阳性浆细胞浸润。超过 90%的 IgG4 相关硬化性胆管炎患者伴有 1 型自身免疫性胰腺炎，其余患者表现为孤立性胆管炎。诊断需要多学科方法，其中病理检查具有关键作用。组织学检查（即胆管活检、肝针活检）很重要，特别是对于孤立性胆管炎患者，因为 IgG4-胆管炎的影像学发现不足以建立诊断。此外，其他胆道疾病也可能出现血清 IgG4 水平轻度升高。IgG4 相关硬化性胆管炎的组织学模拟物包括原发性硬化性胆管炎、滤泡性胆管炎和伴有粒细胞上皮病变的硬化性胆管炎，后两者是最近描述的实体。
