Division of Anatomic Pathology, Mayo Clinic, Rochester, MN 55905.
Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905.
Hum Pathol. 2014 Aug;45(8):1722-9. doi: 10.1016/j.humpath.2014.04.006. Epub 2014 Apr 24.
Extrahepatic bile ducts are the most commonly involved extrapancreatic organ site in patients with type 1 autoimmune pancreatitis. IgG4-related sclerosing cholangitis (IgG4-SC) alone, without evidence of pancreatic or other organ involvement, is uncommon and is difficult to distinguish from cholangiocarcinoma preoperatively. We describe 9 patients with isolated IgG4-SC over an approximate 10-year period, each clinically suspected to have cholangiocarcinoma. We examined the clinical, radiological, cytologic (including fluorescence in situ hybridization results), and histologic features. IgG and IgG4 immunohistochemistry were performed. All 9 patients were middle-aged men who presented with obstructive jaundice. The biliary strictures involved all parts of the extrahepatic biliary tree. Serum IgG4 was slightly elevated in three of eight patients. Cytologic findings were interpreted as negative in six, atypical in one, and suspicious for adenocarcinoma in one. Fluorescence in situ hybridization revealed aneuploidy in one and was equivocal (trisomy 7) in 2. Eight of 9 patients underwent radical resection for suspected cholangiocarcinoma. There was only one case diagnosed with IgG4-SC preoperatively based on biopsy. Histologic sections revealed a prominent lymphoplasmacytic infiltrate with storiform fibrosis and marked increased IgG4-positive plasma cells (≥30/high-power field) in all specimens. Fifty percent of cases (4/8) had IgG4/IgG plasma cell ratio >40%. On median follow-up of 2.8 years, no relapse has occurred in any patient. Extrahepatic IgG4-SC may present as an isolated lesion mimicking cholangiocarcinoma. The diagnosis can be challenging. Clinicians and pathologists should recognize this to avoid major surgery.
肝外胆管是 1 型自身免疫性胰腺炎患者最常累及的胰外器官部位。单独的 IgG4 相关硬化性胆管炎（IgG4-SC），无胰腺或其他器官受累的证据，并不常见，且术前难以与胆管癌相鉴别。我们描述了 9 例在大约 10 年期间内孤立性 IgG4-SC 的患者，每位患者均临床怀疑为胆管癌。我们检查了临床、放射学、细胞学（包括荧光原位杂交结果）和组织学特征。进行了 IgG 和 IgG4 免疫组织化学染色。9 例患者均为中年男性，表现为阻塞性黄疸。胆道狭窄累及肝外胆道的所有部位。8 例患者中的 3 例血清 IgG4 轻度升高。6 例细胞学检查结果判读为阴性，1 例为不典型，1 例为可疑腺癌。荧光原位杂交显示 1 例存在非整倍体，2 例结果为（三体 7）不确定。9 例患者中的 8 例因怀疑胆管癌而接受根治性切除术。仅有 1 例患者术前基于活检诊断为 IgG4-SC。组织学切片显示所有标本均存在明显的淋巴浆细胞浸润、席纹状纤维化和显著增加的 IgG4 阳性浆细胞（≥30/高倍视野）。50%的病例（4/8）具有 IgG4/IgG 浆细胞比例>40%。在平均 2.8 年的随访中，没有任何患者复发。肝外 IgG4-SC 可能表现为孤立性病变，类似于胆管癌。诊断具有挑战性。临床医生和病理科医生应认识到这一点，以避免进行大手术。
