To assess the value of gastroscopic biopsy in the treatment of gastric mucosal lesions by endoscopic submucosal dissection (ESD).

Eighty-five patients with gastric mucosal lesions who underwent gastroscopic biopsy and histopathologic examination as well as ESD and postoperative pathological examination at the Endoscopy Center of the First Affiliated Hospital of Nanchang University from February 2016 to April 2017 were retrospectively studied. The chi square test was used to compare the consistent rate of pathological examinations before and after ESD for lesions with different locations (gastric antrum, gastric angle, gastric body, cardia, gastric fundus, pylorus, and residual stomach), pathological types (low grade neoplasia, high grade neoplasia, and early gastric cancer), or sizes.

The consistent rates of pathological examinations before and after ESD differed significantly for lesions with different locations (66.7%, 16.7%, 22.2%, 28.5%, 50.0%, 50.0%, and 100.0%, respectively; χ²=18.98, P=0.004). The consistent rate was significantly higher for lesions in the gastric antrum than in the gastric angle and body [66.7% (30/45) vs 22.2% (2/9), 16.7% (3/18), χ²=10.96, 4.434, P=0.001, 0.023]. The consistent rates of pathological examinations before and after ESD also differed significantly for lesions with different pathological types (88.9% vs 40.6% vs 34.2%, χ²=15.384, P<0.001). The consistent rate was significantly higher for early gastric cancer than for high grade neoplasia and low grade neoplasia (χ²=12.115, P<0.001; χ²=9.124, P=0.001). The consistent rates of pathological examinations before and after ESD were not statistically significant for lesions with different sizes (38.5% vs 53.3% vs 53.3% vs 44.4%, χ²=1.121, P=0.772). In 35 cases of preoperative low-grade neoplasia, 65.8% (23/35) were under-diagnosed preoperatively, with 40.0% (14/35) being diagnosed as early gastric cancer postoperatively. In 32 cases of high grade neoplasia, 46.9% (15/32) were suggested to be early gastric cancer postoperatively. In total, 44.7% (38/85) of lesions were under-diagnosed preoperatively, of which 76.3% (29/38) were suggested to be cancer postoperatively.

Preoperative diagnosis by gastroscopic biopsy has a low consistent rate with pathological diagnosis after ESD, and it is more likely that gastric mucosal lesions are under-diagnosed preoperatively, especially for patients preoperatively diagnosed with high grade neoplasia.