Sato M, Inoue H, Ogawa S, Ohashi S, Maetani I, Igarashi Y, Sakai Y
Third Department of Internal Medicine, Ohashi Hospital, Toho University School of Medicine, Tokyo, Japan.
Endoscopy. 1998 Mar;30(3):281-8. doi: 10.1055/s-2007-1001255.
Vascular dilatation seen on percutaneous transhepatic cholangioscopy (PTCS) is diagnostic of intramural invasive carcinoma of the bile duct, but the limitations of the technique, including biopsy, for the diagnosis of intramural extension of bile duct carcinoma have not to our knowledge been investigated before. The aims of the present study were to estimate the thickness of the specimens of bile duct wall taken by biopsy, to assess the sensitivity of PTCS for detecting intramural invasive carcinoma, and to identify the characteristics of the intramural extension of bile duct carcinoma associated with vascular dilatation.
A total of 135 biopsy, and 16 surgical specimens obtained from 25 bile duct carcinomas were examined for: the thickness of the biopsy specimens and of the mucosa and combined mucosal-fibromuscular layers in the resected common bile ducts and common hepatic ducts; the presence of muscular and neural bundles in the biopsy specimens; the number of invasive carcinomas in the biopsy specimens that had been taken from stenosed regions; and the relation between intramural extension of invasive carcinoma and vascular dilatation.
The mean thickness of the biopsy specimens did not differ from the mean thickness of the mucosa in the resected specimens, but was significantly lower than that of the combined mucosa and fibromuscular layer. Muscular bundles were included in only 13 (14%) of the biopsy specimens, and there were no neural bundles. Carcinomas and invasive carcinomas were diagnosed histologically from the biopsy specimen in 96% and 91% of the cases, respectively. The sensitivity of a single biopsy for diagnosis for invasive carcinoma in stenosed regions was 62%, almost the same as the sensitivity in non-stenosed regions with vascular dilatation (68%). On histologic examination of 16 resected specimens, the sensitivity and specificity of vascular dilatation as a marker of the intramural extension of an invasive carcinoma were 39% and 100%, respectively, and this was significantly more common in invasive carcinomas that were invading the mucosa beyond the adventitia than in those limited to the adventitia.
Histologic examinations of specimens obtained by PTCS-guided biopsy can detect invasive carcinoma in only the superficial layers of the bile duct, such as the mucosa and the shallowest fibromuscular layer. Multiple specimens are needed for the diagnosis of invasive carcinoma because the sensitivity of examination of a single specimen for detecting invasive carcinoma is low. Vascular dilatation is characteristic of carcinoma that is invading the mucosa beyond the adventitia, so the diagnosis of intramural extension of bile duct carcinoma limited to the adventitia, particularly if it has spread to the deeper fibromuscular layer and the adventitia, is difficult to make by PTCS.
经皮经肝胆道镜检查（PTCS）所见的血管扩张是胆管壁内浸润性癌的诊断依据，但据我们所知，此前尚未对该技术（包括活检）在诊断胆管癌壁内浸润范围方面的局限性进行研究。本研究的目的是评估活检获取的胆管壁标本厚度，评估PTCS检测壁内浸润性癌的敏感性，并确定与血管扩张相关的胆管癌壁内浸润特征。
共检查了从25例胆管癌获取的135份活检标本和16份手术标本，以观察：活检标本以及切除的胆总管和肝总管中黏膜及黏膜-纤维肌层组合的厚度；活检标本中肌束和神经束的存在情况；取自狭窄区域的活检标本中浸润性癌的数量；以及浸润性癌壁内浸润与血管扩张之间的关系。
活检标本的平均厚度与切除标本中黏膜的平均厚度无差异，但显著低于黏膜与纤维肌层组合的厚度。仅13份（14%）活检标本中包含肌束，且无神经束。分别在96%和91%的病例中从活检标本中组织学诊断出癌和浸润性癌。在狭窄区域，单次活检诊断浸润性癌的敏感性为62%，与血管扩张的非狭窄区域的敏感性（68%）几乎相同。对16份切除标本进行组织学检查时，血管扩张作为浸润性癌壁内浸润标志物的敏感性和特异性分别为39%和100%，且在侵犯外膜以外黏膜的浸润性癌中比局限于外膜的浸润性癌更为常见。
经PTCS引导活检获取的标本进行组织学检查仅能检测到胆管表层（如黏膜和最浅的纤维肌层）的浸润性癌。由于单次标本检查检测浸润性癌的敏感性较低，因此诊断浸润性癌需要多个标本。血管扩张是侵犯外膜以外黏膜的癌的特征，因此对于局限于外膜的胆管癌壁内浸润，尤其是已扩散至深层纤维肌层和外膜的情况，很难通过PTCS做出诊断。
