摘要：早期食管癌的诊断对于患者的预后和生存率具有至关重要的影响。然而，早期食管癌在常规内镜检查中往往难以被发现，这使得寻找一种更有效的检测方法成为医学界的当务之急。碘染色内镜筛查技术的出现，为早期食管癌的检测带来了新的曙光，尤其在高危人群的筛查中，展现出了显著的优势

早期食管癌的诊断对于患者的预后和生存率具有至关重要的影响。然而，早期食管癌在常规内镜检查中往往难以被发现，这使得寻找一种更有效的检测方法成为医学界的当务之急。碘染色内镜筛查技术的出现，为早期食管癌的检测带来了新的曙光，尤其在高危人群的筛查中，展现出了显著的优势。本文将基于相关研究成果，详细探讨碘染色内镜筛查在早期食管癌检测中的应用。

碘染色内镜筛查是一种基于化学反应的检测技术。正常食管鳞状上皮细胞含有丰富的糖原，这些糖原能够与碘液发生反应，使得正常组织呈现棕色。而癌变细胞由于糖原含量减少或消失，因此无法着色。这种特性使得碘染色内镜能够清晰地区分正常组织和可疑病变区域，从而提高早期食管癌的检出率。在高危人群中，如头颈部癌症患者或有其他非食管原发性癌症病史的患者，碘染色内镜筛查已被证明是一种有效的检测手段。

(A) Conventional endoscopy shows a reddish, rough mucosal area on the right side of the middle thoracic esophagus. (B) The lesion is evaluated as a clearly distinguishable brownish area by narrow band imaging endoscopy. (C) Lugol chromoendoscopy indicates a clearly distinguishable iodine-unstained area measuring approximately 40 mm or less in diameter.

在一项针对非食管原发性癌症患者的前瞻性研究中，研究人员对331名年龄在55岁及以上的男性患者进行了碘染色内镜检查。研究结果显示，有9名患者（2.7%）被诊断出患有浅表食管癌。其中，7名患者为黏膜内癌，通过内镜黏膜切除术得到了有效治疗；另外2名患者的癌症已侵犯至黏膜下层，接受了手术切除或放射治疗。值得注意的是，在这些被确诊的患者中，有5名患者的癌灶仅局限于上皮层或固有层，这类病变在传统的内镜筛查中极难被察觉，但得益于碘染色技术，它们得以被精准识别，并通过内镜黏膜切除术实现了治愈。此外，即使排除了头颈部癌症患者后，剩余280名患者中浅表食管癌的发病比例仍高达2.1%，这一数据显著高于以往筛查研究的报道结果。这表明，对于有非食管原发性癌症病史的男性患者而言，进行内镜筛查是十分必要的，而碘染色技术在早期食管癌的筛查过程中具有不可忽视的重要作用。

尽管碘染色内镜筛查在早期食管癌的检测中具有显著的优势，但也存在一些局限性和需要注意的问题。首先，碘染色内镜检查可能会引起化学性食管炎，导致患者出现胸骨后不适、糜烂或溃疡等不良反应。其次，碘染色内镜检查的准确性可能受到多种因素的影响，如 Lugol 氏液的浓度、内镜检查的时间间隔等。高浓度的 Lugol 氏液可能会增加黏膜损伤的风险，而过长的检查间隔可能导致肿瘤的进展，从而影响治疗效果。因此，在进行碘染色内镜筛查时，必须谨慎选择 Lugol 氏液的浓度，并合理安排检查与治疗之间的时间间隔，以减少对患者的不良影响。

随着医学技术的不断发展，新的图像增强内镜（IEE）技术如窄带成像（NBI）和 I-scan 技术等，已被报道在早期食管癌的检测中具有潜在的应用价值。这些新技术如果能够进一步发展，使得内镜医生能够在不使用 Lugol 氏液的情况下检测早期食管癌并确定其水平范围，那么在治疗时出现再上皮化的问题可能会得到解决。然而，目前仍需要更多的研究来比较这些新技术与碘染色内镜在检测和界定早期食管癌方面的诊断能力。

(A) At the time of treatment, the oral border of the tumor is unclear by conventional endoscopy. (B) The lesion is observed as a brownish area with a vague border and can only be barely demarcated by magnifying endoscopy with narrow band imaging. (C) Intraoperative iodine staining reveals a 25 mm iodine-unstained area and many other small unstained areas scattered on the oral side. The marking (white arrowhead) corresponds to the oral margin of the iodine-unstained area, which was observed by preoperative endoscopy.

碘染色内镜筛查作为一种有效的早期食管癌检测手段，尤其在高危人群的筛查中具有重要的应用价值。通过碘染色内镜检查，可以显著提高早期食管癌的检出率，为患者提供更及时的治疗机会，从而改善患者的预后和生存率。然而，在应用碘染色内镜筛查时，也需要注意其可能引起的不良反应，并采取相应的措施加以预防和处理。未来，随着新的图像增强内镜技术的不断进步，有望进一步提高早期食管癌的检测水平，为患者的治疗和康复带来更大的益处。

Histopathological assessment revealed proliferation of atypical squamous cells limited to the mucosal epithelium, indicating high-grade intraepithelial neoplasia. The tumor size was 35 mm in diameter. Both lateral and vertical margins were tumor-free, and there was no vessel infiltration. The extent of tumor cells seemed to coincide with the preoperative assessment (Fig. 4). Tumor cells were also found in the basal-parabasal layers of the mucosa where small unstained areas were scattered, although superficial layers showed well-differentiation containing glycogen in cytoplasm.

(A) Histopathologically, atypical squamous cells spread to the mucosa, in which small unstained areas are scattered. The white lines correspond to the main iodine-unstained area. The green lines correspond to the mucosa, in which small unstained areas are scattered. The yellow arrow corresponds to the white arrow in Fig. 2C. Histological images of (B) hematoxylin-eosin and (C) periodic acid-Schiff staining, demonstrating the border area between the atypical squamous epithelium and the non-neoplastic squamous epithelium (blue arrowhead in Fig. 4A, ×100). Atypical squamous cells are not stained by the periodic acid-Schiff stain, corresponding to the main iodine-unstained area. Histological images of (D) hematoxylin-eosin and (E) periodic acid-Schiff staining, demonstrating the mucosa in which small unstained areas were observed by intraoperative iodine staining (pink arrowhead in Fig. 4A, ×100). Atypical squamous cells are found in the basal-parabasal layers, although the superficial layer presents well-differentiated cells containing glycogen in the cytoplasm.

参考文献：

[1] Asada-Hirayama I, Ono S, Kodashima S, et al. Preoperative iodine staining may complicate the demarcation of esophageal carcinoma. Gut Liver. 2013 Jul 11;7(4):492-496. doi:10.5009/gnl.2013.7.4.492.

[2] Shimizu Y, Tukagoshi H, Fujita M, et al. Endoscopic screening for early esophageal cancer by iodine staining in patients with other current or prior primary cancers. Gastrointest Endosc. 2001;53(1):1-5. doi:10.1067/mge.2001.111387.

[3] Ono S, Fujishiro M, Koike K. Endoscopic submucosal dissection for superficial esophageal neoplasms. World J Gastrointest Endosc. 2012;4(5):162-166. doi:10.4253/wjge.v4.i5.162.

[4] Dawsey SM, Fleischer DE, Wang GQ, et al. Mucosal iodine staining improves endoscopic visualization of squamous dysplasia and squamous cell carcinoma of the esophagus in Linxian, China. Cancer. 1998;83(1):220-231.

[5] Shiozaki H, Tahara H, Kobayashi K, et al. Endoscopic screening of early esophageal cancer with the Lugol dye method in patients with head and neck cancers. Cancer. 1990;66(10):2068-2071. doi:10.1002/1097-0142(19901115)66:103.0.co;2-w.

[6] Kondo H, Fukuda H, Ono H, et al. Sodium thiosulfate solution spray for relief of irritation caused by Lugol's stain in chromoendoscopy. Gastrointest Endosc. 2001;53(2):199-202. doi:10.1067/mge.2001.110730.

[7] Myung Park J, Seok Lee I, Young Kang J, et al. Acute esophageal and gastric injury: complication of Lugol's solution. Scand J Gastroenterol. 2007;42(1):135-137. doi:10.1080/00365520600825141.

[8] Lee CT, Chang CY, Lee YC, et al. Narrow-band imaging with magnifying endoscopy for the screening of esophageal cancer in patients with primary head and neck cancers. Endoscopy. 2010;42(6):613-619. doi:10.1055/s-0030-1255514.

[9] Kodashima S, Fujishiro M. Novel image-enhanced endoscopy with i-scan technology. World J Gastroenterol. 2010;16(9):1043-1049. doi:10.3748/wjg.v16.i9.1043.

来源：医学顾事