Langerhans cell histiocytosis (LCH) is a rare group of idiopathic disorders (previously termed “histiocytosis X”) which is characterized by the presence of cells with characteristics similar to bone marrow-derived Langerhans cells which infiltrate various tissues and organs. Like Langerhans cells located in the skin, they express histiocytic markers such as S100, CD1a, and CD68 and contain Birbeck granules, which are rod-shaped intracytoplasmic organelles best demonstrated in electron microscopy. LCH primarily affects the skeleton, but lung, skin, liver, and lymph node involvement may occur alike. Hepatic involvement is well recognized in children, with sclerosing cholangitis occurring in 10–15% of those with multisystemic involvement, whereas LCH confined to the liver appears to be very unusual in adults. Up to date, only one case of a solitary LCH affliction of the extrahepatic bile duct lacking liver involvement in adulthood has been reported on in the literature. We here report on a 60-year-old male patient with classical indolent progressive obstructive jaundice. The diagnostic workup revealed a tumorous lesion in the middle third of the common hepatic bile duct, initially being highly suspicious of an extrahepatic cholangiocarcinoma. CT scans further suspected an infiltration of the right portal vein, implicating a potentially extensive tumor growth, but a preoperative histological confirmation was not feasible. The serum tumor marker CA19-9 was 48 U/mL. The patient then underwent an explorative laparotomy with a pylorus preserving pancreaticoduodenectomy, as all frozen section tissue specimens revealed no tumor infiltration. The final result of the histopathological examination revealed an isolated LCH in the extrahepatic bile duct with a consecutive secondary sclerosing cholangitis. To complete the tumor staging, a thorax CT scan was performed and a generalized histiocytosis was ruled out, hence confirming the localized character of the disease. To the best of our knowledge and after a comprehensive literature review, we report on the second case globally, which describes a primary LCH limited to the extrahepatic bile duct in adulthood. A generalized sclerosing cholangitis in the liver was ruled out by radiological imaging. Preoperative histological affirmation of such findings is very confined due to the complexity and hence can only be diagnosed in the postoperative specimen. However, patients with nondisseminated sole findings, usually report a good prognostic outcome after surgical resection despite the paucity of corresponding data.
Visc Med

中文翻译：

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成人梗阻性黄疸的一个极其罕见的原因：肝外胆管的有限朗格汉斯细胞组织细胞增生症

朗格汉斯细胞组织细胞增生症 (LCH) 是一组罕见的特发性疾病（以前称为“组织细胞增生症 X”），其特征是存在具有与骨髓来源的朗格汉斯细胞相似的特征的细胞，这些细胞浸润各种组织和器官。与位于皮肤中的朗格汉斯细胞一样，它们表达组织细胞标志物，如 S100、CD1a 和 CD68，并含有伯贝克颗粒，这是在电子显微镜下最能体现的杆状细胞质内细胞器。LCH 主要影响骨骼，但肺、皮肤、肝脏和淋巴结受累也可能相似。肝脏受累在儿童中得到广泛认可，10-15% 的多系统受累患者发生硬化性胆管炎，而仅限于肝脏的 LCH 在成人中似乎非常罕见。最新，文献中仅报道了 1 例成年期肝外胆管无肝受累的孤立性 LCH 病变。我们在这里报告一名 60 岁的男性患者，患有典型的惰性进行性梗阻性黄疸。诊断检查显示肝总胆管中三分之一处有肿瘤性病变，最初高度怀疑肝外胆管癌。CT 扫描进一步怀疑右门静脉浸润，暗示潜在的广泛肿瘤生长，但术前组织学确认是不可行的。血清肿瘤标志物 CA19-9 为 48 U/mL。患者随后接受了剖腹探查术和保留幽门的胰十二指肠切除术，因为所有冰冻切片组织标本均未显示肿瘤浸润。组织病理学检查的最终结果显示肝外胆管中存在孤立的 LCH，并伴有继发性硬化性胆管炎。为了完成肿瘤分期，进行了胸部 CT 扫描并排除了全身性组织细胞增多症，从而确认了疾病的局部特征。据我们所知，在全面的文献回顾之后，我们报告了全球第二例病例，该病例描述了成年期局限于肝外胆管的原发性 LCH。放射成像排除了肝脏中的广泛性硬化性胆管炎。由于复杂性，此类发现的术前组织学确认非常有限，因此只能在术后标本中诊断。然而，具有非播散性鞋底表现的患者，
粘性医学