ABSTRACT
Objective The laterally spreading tumor (LST) of the large intestine have received a great deal of study in Japan, but no report of such cases was found in China. We here of report 46 cases of LST (47 lesions, because one of the patients was found to have two lesions) diagnosed in our hospital in last two years. The morphological features under endoscopy, pit pattern, pathology and treatment under endoscopy were studied. Methods The 47 lesions of LST were found in a total of 5 735 patients who underwent colonoscopic examination in the last two years (from 01-12-2000 to 30-11-2002). The site, size and morphological features of LST were recorded, and the pit pattern was classified with magnification. 42 patients (totally 42 lesions) received colonoscopic surgery, and the rest refused to accept endoscopic therapy, therefore only a biopsy was done for pathological study. In those patients who accepted colonoscopic surgery, 14 patients were treated by mucosal resection (EMR) after injection of saline solution, 24 were treated by piecemeal mucosal resection (EPMR) after injection of saline solution, in 3 patients the lesion was removed by high frequency loop resection, and Cap-EMR was performed using distal hyaline hat attachment fitted to the end of endoscope. The resected or biopsy specimens were studied pathologically. Results 47 lesions of LST were found in a total of 5863 patients who underwent colonoscopic examination. The distrihution of LST lesions were as follows. 22 lesions were situated in the rectum, 10 lesions in the sigmoid colon, 7 lesions in the descending colon, 4 lesions in the transverse colon, 2 lesions in the ascending colon, and 2 lesions were located in the cecum. Macroscopic type: 25 lesions were homogeneous granular type, 12 lesions were mixed nodular granular type, 8 lesions were flat elevated type, and 2 lesions were pseudo-depressed type. The pit pattern as revealed under magnifying endoscopy indicated that 2 lesions were of type II pit, 8 lesion of type II+III L pit, 9 lesions of type III L pit, and 28 lesions of type IV. The pathological diagnosis revealed that 28 lesions were villous adenomas in which 7 lesions showed early malignant degeneration (6 intramucosal cancer and 1 submucosal cancer). 11 lesions were tubular adenomas, in which 1 was intramucosal cancer, 2 lesions were hyperplastic polyp, and 6 lesions were mixed hyperplastic polyps (serrated adenomas). Conclusion The LST manifest some special features, and their incidence may be higher in China than in Japan. EMR or EPMR may be considered as a good method for treatment for LST.
ABSTRACT
Objective To eraluate the methods and results of endoscopic mucosal resections for colonic laterally spreading tumors with early malignant degeneration. Methods The pit pattern was studied with magnitying colonoscopy and mucosal staining technique for colonic laterally spreading tumors (LST) undergoing early earcinatous degeneration. They were removed with endoscopic mucosal resection techniques. A follow-up study was made. Results Eight patients suffering from early carcinoma on top of colonic laterally spreading tumors were followed-up. ① 75% of the lesions were situated in the rectum, sigmoid colon and decending colon. ② 75% of the lesions were larger than 30mm in diameter. ③ 75% of the lesions belonged to Ⅳpit pattern. ④ 62.5% of the lesions were Villous adenomas and 75% of the onalignant change involved the mucosa only. ⑤ All the lesions were completely removed by EMR, ⑥ No local residual lesion, recurrence or metastasis was discovered in all the patients after a mean follow-up period of 20.7 months. Conclusions Most of the early carcinomas originated from colonic LST involved the mucosa only. Endoscopic mucosal resection may be a curative method for the early cancer arising from colonic LST.
ABSTRACT
Objectives In order to further investigate the biological characteristics and the developmental mechanisms of laterally spreading tumor, a cell line from the primary culture of human colon LST tissue was isolated. After 70 passages, we identified the cells by morphologic, genetic and immunohistochemistry analysis. Results (1) The origin of LST cells is epithelial, and the majority of which were multiform epithelial cells. It displayed an approximately similar growth characteristics of tumor cells. The nest corpus doubling time was 36 hours. (2) The number of chromosome is 42-66. Eighty-five percent of chromosomes were triploid, showing abnormal karyotypes. (3) Immunohistochemistry showed that ESA and CK20 were expressed. (4) The ultrastructure of LST was almost the same as that of a tumor cell. Conclusion A novel LST cell line has been established and named as LST-R1. It facilitates further study of the biological characteristics of LST cells and the development of colon cancer.