Objective      To evaluate the correlation between endoscopic morphology of the colorectal laterally spreading tumor (LST) with the pathological type.       Methods      The clinical data of 165 LST patients who had endoscopic or surgical treatment were retrospectively analyzed. In the 165 patients

126 underwent endoscopic treatment

and 22 underwent surgical treatment.       Results      Among the 165 cases

there were 9 cases of homogeneous granular type (LST-G-H)

124 cases of nodular mixed type (LST-G-M)

32 cases of flat elevated type (LST-NG-F)

and 0 case of pseudo-depressed type (LST-NG-PD). The pathology results showed that there were 16 cases of canceration

74 cases of low-grade intraepithelial neoplasia (LGIN)

55 cases of high-grade intraepithelial neoplasia (HGIN) and 20 cases of adenomatous polyp. The incidence of HGIN and submucosal carcinoma of LST-G-M was 47.58% (59/124)

which was higher than that of LST-G-H (22.22%

2/9)

but there was no significant difference. The incidence of HGIN and submucosal carcinoma of LST-NG-F was 31.25% (10/32). Totally

the proportion of pathological types of each endoscopic type of LST had no significant difference (Chi square=7.6301

P=0.2665). The endoscopic type and pathological type had no significant difference in the morphological feature distribution proportion (P0.05). But between the granular type and the non-granular type

the distribution difference of the LGIN

HGIN and cancer was remarkably significant (P0.01).       Conclusion      The endoscopic morphology of LST has certain particularity

is closely associated with colorectal cancer

and is numerously located in the rectum. The canceration rate and malignant potential of each endoscopic type of LST are relatively high

which requires more attention and corresponding treatment measures.