Résumé
BACKGROUND/AIMS: Many endoscopists in Korea lack an understanding of laterally spreading, or creeping tumors(LSTs) which characteristically grow laterally, as opposed to other polypoid lesions, and which show superficially elevated lesions. An LST is similar in color to the adjacent normal mucosa, so it is difficult to recognize, but it can be detected by chromoscopy. When it grows to over 2-3 cm in its largest diameter, it can have malignant foci. It is important not to overlook the lesion and to remove it in a timely manner. METHODS: The authors experienced 9 cases of LSTs from Jan. 1996 to Jan. 1997. We reviewed those 9 cases clinically, endoscopically, and pathologically, and tried to establish the diagnostic and therapeutic key points. RESULTS: The most common age group was the fifth decade. The male-to-female ratio was 5:4. Four cases were asymptomatic, and lower abdominal pain and rectal bleeding were seen in 2 cases respectively. The rectum and the sigmoid colon were the most commonly involved sites showing 88.9% (8/9). Granular-type(nodule-aggregating-type) LSTs were seen in 4 cases and nongranular types(non-noodule-aggregating type) in 5 cases. 66.7%(6/9) were larger than 2 cm in the largest diameter. A tubular adenoma was seen in each of 5 cases; among them, 1 case had cellular atypia and another case revealed a submucosal(sm) carcinoma. Two granular types with large nodules had mucosal carcinomas. The sm carcinoma was a nongranular type. Endoscopically, redness was observed in 66.7%(6/9) of the cases and depression in 33.3%(3/9). The sm carcinoma had both redness and depression. Three cases underwent endoscopic piecemeal mucosal resection(EPMR) and the other 3 cases underwent endoscopic mucosal resection (EMR). A low anterior resection was performed on one patient; there was no lymph node metastasis. CONCLUSIONS: The characteristics of LSTs are important in their diagnosis and management. Nongranular-type LSTs are not uncommon, despite the difficulty in recognizing them by endoscopy. Pathologically, LSTs, in general, are tubular or tubulovillous adenomas. When they are over 2 cm in their largest diameter, they are likely to have malignancies. Giant nodule, redness and depression are important features indicating malignancy, especially an sm carcinoma. An EPMR or an EMR is the main treatment option, but depending on the depth of invasion, surgical resection may need to be considered.