Pathological basis of endoscopic mucosectomy of superficial esophageal carcinoma
Stomach and Intestine 28(2): 125-132
ISSN/ISBN: 0536-2180 Accession: 009163106
Endoscopic mucosectomy of esophageal cancer is now performed in several institutes. To determine the indication for endoscopic mucosectomy, pathological basis was analyzed in 117 lesions. Eighty seven lesions were from 61 operated cases of surperficial carcinoma, and the other lesions were accompanied with advanced cancers. They were composed of 35 ep-cancers, 29 mm-cancers and 53 sm-cancers. Mm-cancers and sm-cancers were subclassified into mm-1, mm-2, mm-3 and sm-1, sm-2, sm-3 respectively. Vascular invasion and lymph node metastasis were analyzed based on this subclassification. In ep-cancers, neither vascular invasion nor lymph node metastasis was found, suggesting that the ep-cancer was an absolute indication for endoscopic mucosectomy. The characteristics of mm-1-cancer was almost similar to those of ep-cancer, because the mm-1-cancer still had most of the continuous basement membrane. One out of five mm-3-cancers had lymph node metastasis and vascular invasion. Thus, mm-3-cancer was not an indication for endoscopic mucosectomy. There was controversy over the indication of mm-2 cancer. Even though none of seven cases in our studies has vascular invasion and lymph node metastasis, the lamina propria mucosa of the esophagus has rich networks of the lymphatics and vessels, further study should be done concerning histological type and mode of invasion of carcinoma in relation to lymphatic invasion and lymph node metastasis in mm-2-cancer. Another problem was multifocality of the esophageal cancer. The incidence of multifocal esophageal cancers was very high as 20 apprx 30%. A careful follow up should be continued after mucosectomy. The purpose of endoscopic mucosectomy for cancer was complete resection. Therefore, histological examination of the resected specimen was essential. We demonstrated how to fix and examine the resected specimen with photographs.