Department of Gastroenterology, Dokkyo Medical University, 880 Kitakobayashi, Mibu, Shimotsuga-gun, Tochigi 321-0293, Japan.
World J Gastroenterol. 2010 Jan 14;16(2):237-44. doi: 10.3748/wjg.v16.i2.237.
To assess the diagnostic ability of endoscopic ultrasonography (EUS) for evaluating causes of distal biliary strictures shown on endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP), even without identifiable mass on computed tomography (CT).
The diagnostic ability of EUS was retrospectively analyzed and compared with that of routine cytology (RC) and tumor markers in 34 patients with distal biliary strictures detected by ERCP or MRCP at Dokkyo Medical School Hospital from December 2005 to December 2008, without any adjacent mass or eccentric thickening of the bile duct on CT that could cause biliary strictures. Findings considered as benign strictures on EUS included preservation of the normal sonographic layers of the bile duct wall, irrespective of the presence of a mass lesion. Other strictures were considered malignant. Final diagnosis of underlying diseases was made by pathological examination in 18 cases after surgical removal of the samples, and by clinical follow-up for > 10 mo in 16 cases.
Seventeen patients (50%) were finally diagnosed with benign conditions, including 6 "normal" subjects, while 17 patients (50%) were diagnosed with malignant disease. In terms of diagnostic ability, EUS showed 94.1% sensitivity, 82.3% specificity, 84.2% positive predictive value, 93.3% negative predictive value (NPV) and 88.2% accuracy for identifying malignant and benign strictures. EUS was more sensitive than RC (94.1% vs 62.5%, P = 0.039). NPV was also better for EUS than for RC (93.3% vs 57.5%, P = 0.035). In addition, EUS provided significantly higher sensitivity than tumor markers using 100 U/mL as the cutoff level of carbohydrate antigen 19-9 (94.1% vs 53%, P = 0.017). On EUS, biliary stricture that was finally diagnosed as malignant showed as a hypoechoic, irregular mass, with obstruction of the biliary duct and invasion to surrounding tissues.
EUS can diagnose biliary strictures caused by malignant tumors that are undetectable on CT. Earlier detection by EUS would provide more therapeutic options for patients with early-stage pancreaticobiliary cancer.
评估内镜超声（EUS）对经内镜逆行胰胆管造影术（ERCP）或磁共振胰胆管造影术（MRCP）显示的远端胆管狭窄的诊断能力，即使在 CT 上未发现可识别的肿块也是如此。
回顾性分析 2005 年 12 月至 2008 年 12 月期间在独协医科大学医院，因 ERCP 或 MRCP 发现的 34 例远端胆管狭窄患者的 EUS 诊断能力，并与常规细胞学（RC）和肿瘤标志物进行比较，这些患者的 CT 上没有相邻的肿块或胆管偏心性增厚，这些都可能导致胆管狭窄。EUS 认为良性狭窄的表现为胆管壁的正常超声层，无论是否存在肿块病变。其他狭窄被认为是恶性的。18 例患者在手术切除标本后通过病理检查，16 例患者通过 > 10 个月的临床随访确定了潜在疾病的最终诊断。
最终诊断为良性疾病的患者有 17 例（50%），其中 6 例为“正常”，而诊断为恶性疾病的患者有 17 例（50%）。在诊断能力方面，EUS 对识别恶性和良性狭窄的敏感度为 94.1%，特异度为 82.3%，阳性预测值为 84.2%，阴性预测值（NPV）为 93.3%，准确率为 88.2%。EUS 比 RC 更敏感（94.1%比 62.5%，P = 0.039）。EUS 的 NPV 也优于 RC（93.3%比 57.5%，P = 0.035）。此外，EUS 在使用 100 U/mL 作为糖抗原 19-9 的截断值时，其敏感性显著高于肿瘤标志物（94.1%比 53%，P = 0.017）。在 EUS 上，最终诊断为恶性的胆管狭窄表现为低回声、不规则的肿块，胆管阻塞和周围组织侵犯。
EUS 可诊断 CT 无法检测到的恶性肿瘤引起的胆管狭窄。EUS 的早期检测可为早期胰胆管癌患者提供更多的治疗选择。
