Analysis of clinical and pathological characteristics of 266 cases of colorectal laterally spreading tumor / 中华消化杂志

ABSTRACT

Objective:To analyze the clinical and pathological characteristics of colorectal laterally spreading tumor (CLST) and provide reference for clinical diagnosis and treatment of CLST.Methods:From January 1, 2016 to June 30, 2021, the clinical data of patients with CLST who underwent endoscopic resection at the Second Affiliated Hospital of Dalian Medical University were retrospectively collected. The clinical and pathological characteristics of CLST were analyzed in terms of lesion location (right colon, left colon, rectum) and morphological type (granular-homogeneous type, granular-mixed type, flat-elevated type, and pseudo-depressed type). One-way analysis of variance, Pearson′s chi-square test and Fisher′s exact test were used for statistical analysis.Results:A total of 266 patients with CLST and 296 CLST lesions were included. The most common maximum diameters of the lesions were 10 to 29 mm, accounting for 85.1% (252/296). The main morphological type was granular type, accounting for 81.4% (241/296), and the main pathological type was adenoma, accounting for 79.7% (236/296), and the most common histological type was low-grade intraepithelial neoplasia (LGIN), accounting for 81.1% (240/296). The maximum diameter of CLST lesion of rectum was larger than that of the right colon and the left colon ((24.20±16.97), (18.38±8.24) and (18.59±7.95) mm, respectively), and the difference was statistically significant ( F=6.62, P<0.001). The detection rate of granular-homogeneous type CLST in rectum was lower than that in the right colon and the left colon (22.0%, 11/50, 53.5%, 69/129 and 58.9%, 69/117, respectively), while the detection rate of granular-mixed type CLST in rectum was higher than that in the right colon and the left colon (50.0%, 25/50; 29.4%, 38/129 and 24.8%, 29/117, respectively), and the differences were statistically significant ( χ2=20.06 and 10.67, both P<0.01). The incidence of adenoma in CLST in the right colon was lower than that in the left colon and rectum (68.2%, 88/129; 87.2%, 102/117 and 92.0%, 46/50, respectively), while the incidence of serrated adenoma in CLST in the right colon was higher than that in the left colon and rectum (30.2%, 39/129; 12.8%, 15/117 and 4.0%, 2/50, respectively), and the differences were statistically significant ( χ2=19.25 and 20.85, both P<0.001). The CLST in left colon was mostly treated by endoscopic submucosa dissection (94.9%, 111/117), while the CLST in rectum was mostly treated by endoscopic mucosal resection (20.0%, 10/50), and the difference was statistically significant ( χ2=8.77, P=0.012). The maximum diameter of the pseudo-depressed type CLST was larger than that of the granular-homogeneous type, granular-mixed type and flat-elevated type ((24.18±14.07), (15.96±5.70), (23.49±13.80) and (21.21±8.02) mm), and the difference was statistically significant ( F=13.40, P<0.001). The incidence of adenoma in flat-elevated type CLST was higher than that of the granular-homogeneous type, granular-mixed type and pseudo-depressed type (92.1%, 35/38; 71.1%, 106/149; 86.9%, 80/92 and 15/17, respectively), and the difference was statistically significant ( χ2=14.13, P=0.003). The incidence of serrated adenoma in the granular-homogeneous type CLST was higher than that of the granular-mixed type, flat-elevated type and pseudo-depressed type (28.9%, 43/149; 10.9%, 10/92; 5.3%, 2/38 and 1/17, respectively), and the difference was statistically significant ( χ2=19.98, P<0.001). The incidence of adenocarcinoma in the pseudo-depressed type CLST was higher than that of the granular-homogeneous type, granular-mixed type and flat-elevated type (1/17; 0, 0/149; 2.2%, 2/92 and 2.6%, 1/38, respectively), and the difference was statistically significant (Fisher′s exact test, P=0.049). The incidence of LGIN in the granular-homogeneous type CLST was higher than that of the granular-mixed type, flat-elevated type and pseudo-depressed type (90.6%, 135/149; 76.1%, 70/92; 65.8%, 25/38 and 10/17, respectively), while the incidences of high-grade intraepithelial neoplasia and carcinoma in the pseudo-depressed type CLST were higher than those of the granular-homogeneous type, granular-mixed type and flat-elevated type (6/17; 9.4%, 14/149; 21.7%, 20/92; 31.6%, 12/38 and 1/17; 0, 0/149; 2.2%, 2/92 and 2.6%, 1/38), and the differences were statistically significant( χ2=21.58 and 16.81 and Fisher′s exact test, all P<0.05). Conclusions:The clinicopathological characteristics of CLST have certain specificity. The maximum diameter and malignant potential of the rectal CLST are both larger and higher than those of the colonic CLST. Although the granular-mixed type CLST is the granular type, it shows a larger maximum diameter and a higher degree of malignancy.