Adequate endoscopic mucosal resection for early gastric cancer obtained from the dissecting microscopic features of the resected specimens

Background. We have employed endoscopic mucosal resection (EMR), using a cap-fitted panendoscope (EMRC), for early gastric cancer since 1992. The presence of an adequate surgical margin is a requirement because of the radicality of EMR, and dissecting microscopic examination is useful in regard to the diagnosis of spread of the disease. Methods. To devise an adequate method of EMR that allows no lateral residue, we examined gastric mucosal specimens obtained by EMRC. One hundred and sixty-seven specimens from 97 lesions in 85 patients treated by EMRC were examined in regard to characteristic features, the recovery of marks made around the lesion, and the frequency of residue, and comparisons were made between the dissecting microscopic and histopathological findings. Results. The first specimen obtained with a large cap under full suction was a circular shape measuring 21 × 19 mm. The second specimen from fractionated resection was a half-moon or crescent shape, and the third specimen had a ginkgo leaf-like or irregular shape. In the elevated lesions, coincidence regarding the spread, as determined by dissecting microscopy and histopathology, was present in 62 (93%) of the 67 lesions. In 16 (53%) of 30 flat or depressed lesions, there was a difference of 2 to 5 mm between the spread determined by these two examinations. Conclusion. It is important to place an adequate number of marks around the lesion and recover all marks by resection. When an elevated lesion measures 15 mm or more, and a flat or depressed lesion is not clearly demarcated, aggressive use of planned fractionated resection seems to be the best way to prevent a lateral residue in EMR. Received: February 1, 2001 / Accepted: July 3, 2001