[Endoscopic evaluation of the depth of invasion in cases of superficial esophageal cancer in determining indications for endoscopic mucosal resection].

Endoscopic mucosal resection (EMR) should be performed for the treatment of squamous cell carcinoma of the esophagus limited to the lamina propria mucosae (m1 and m2 cancers), because lymph node metastasis is rare in these cases. The lymph node metastasis rate is 6% when cancers reach the muscularis mucosa(m3) or slightly invade the submucosa (sm1). Lymph node metastasis is noted in 47% of esophageal cancers moderately or severely invading the submucosa(sm2 and sm3). Radical esophagectomy is recommended for sm2 and sm3 disease. Type 0-II cancers are candidates for EMR, because 86% remain within the mucosa, while 90% of type 0-I lesions and 96% of type 0-III lesions are submucosal cancers. Among type 0-II cancers, most type 0-IIb lesions are m1 cancer. Among type 0-IIa cancers, 96% are mucosal. Type 0-IIc lesions are frequent among superficial esophageal cancers and 19% reach the submucosa. Endoscopic diffrentiation of m1 and m2 cancers is reliable, since 96% of all m1 and m2 cancers were correctly diagnosed before treatment. In cases with type O-IIc lesions which is most frequent among superficial esophageal cancers, m1 cancer showed very slight depressions with a smooth surface and reddening. Sometimes fine granular changes are seen. They are also delineated as an unstained area by endoscopic toluidine blue-iodine double staining. They showed very slight depressions with a smooth surface and reddening. Sometimes fine granular changes are seen. They are also delineated as an unstained area by endoscopic toluidine blue-iodine double staining. Dark blue dots, spots, or reticular staining are frequently identified in m2 cancers. In cases with m3 or sm1 cancer, coarse granular changes, small nodular elevations, or slightly deeper depressed areas in the m1 and m2 lesions suggest sites of deeper invasion.