Korean experience of superficial depressed‐type early colorectal cancer

Background: Unlike the adenoma–carcinoma sequence theory, the de novo carcinoma theory has been highlighted recently because of the emergence of superficial depressed‐type early colorectal cancers. In addition, some flat‐elevated or sessile‐type early colorectal cancers have been identified as originating from superficial depressed‐type early colorectal cancers. Thus, studies of superficial depressed‐type early colorectal cancers may provide an opportunity to clarify the morphogenesis of colorectal cancers in the foreseeable future. Methods: The authors studied 231 cases of early colorectal cancer from 1997 to 2000. Among them, 17 cases (7.4%) were superficial depressed‐type. According to Kudo's classification, the 17 lesions were classified as three types based on their growth patterns: IIc, IIa + IIc, and Is + IIc. They were also classified as sm‐s (sm₁) and sm‐m (sm_2–3) cancers based on the depth of submucosal invasion according to Kudo's classification. They were analyzed with emphasis on size, depth of submucosal invasion and treatment. Results: Type IIc lesions were 11 mm in diameter on average; types IIa + IIc and Is + IIc had diameters of 15 mm and 11 mm on average, respectively. Sm‐m cancers' diameters were all larger than 10 mm. Fifty‐seven percent (57%) of type IIc cancers were submucosally invasive, while 90% of type IIa + IIc and type Is + IIc cancers together were submucosally invasive. The overall surgical resection rate was 41.2%, and surgical resection was performed in 80% of the sm‐m cases. Conclusion: Recognition of superficial depressed‐type early colorectal cancers, especially type IIa + IIc and type Is + IIc cancers, is important because their biological behavior will most likely be different from that of the usual protruding early cancers. Accordingly, the treatment modality should be selected prudentially, and early detection is imperative in order for their sizes to be less than 10 mm.     

Endoscopic Therapy of Early Gastric Cancer —Comparison of Endoscopic Mucosal Coagulation and Resection—

Abstract: The clinical efficacy of various methods of endoscopic treatment was evaluated in 70 patients with early gastric cancer. The treatments included using an Nd- YAG laser on 22 patients (2 IIa cases, 3 IIa + IIc cases and 17 IIc cases), a heater probe on 2 patients (IIc) and endoscopic mucosal resection (EMR) on 46 patients (13 I cases, 15 IIa cases, 2 IIa + IIc cases and 16 IIc cases). Laser irradiation and the heater probe method (endscopic mucosal coagulation; EMC), which cause coagulation and necrosis to lesions using heat energy, were found to be successful for well differentiated adenocarcinoma confined to the mucosa even if the size of the lesions was 20 mm and over. Poorly differentiated adenocarcinoma with lesions 20 mm or smaller reoccurred, and only well differentiated adenocarcinoma with infiltration limited to the mucosa seemed to be treatable endoscopically by EMR. Whether or not total resection was possible was determined with respect to the size and site of lesions in patients treated by EMR. Great therapeutic efficacy was achieved when the lesions were 10 mm or smaller and located in the anterior wall or the greater curvature. Piecemeal resection had to be made in a majority of cases when the lesions measured 10 mm or more or were located in the lesser curvature or the posterior wall. Therefore, endoscopic EMR is recommended if the size of the lesions is 10 mm or less, while EMC must also be considered if the lesions are larger or piecemeal resection is required.     

A Type IIc Like Advanced Carcinoma of the Sigmoid Colon —A Case Report—

Abstract: We studied a patient with a sigmoid colon carcinoma, which looked like a type IIc carcinoma when it was, in fact, an advanced carcinoma. This lesion was considered to have developed from an early carcinoma with a depressed appearance. A 79-year-old woman was admitted complaining of a small amount of rectal bleeding. A barium enema examination revealed a flat elevated lesion with converging folds. A colonoscopy revealed a slightly reddish lesion with a central depression 40～50 cm from the anal verge. A biopsy specimen revealed the features of a well differentiated adenocarcinoma. A sigmoidectomy with lymph node dissection was performed. The resected specimen showed a tumor which looked like a so-called type IIc advanced carcinoma, measuring 10×6 mm in size. This lesion was histologically diagnosed as being a well differentiated adenocarcinoma without any adenomatous component. The tumor showed a massive invasion into the submucosal layer and a slight invasion into the proper muscle layer.     

Clinical Experiences with Laparoscopic Colectomy

Abstract: The indications for laparoscopic colon resection and the associated complications are discussed herein. This procedure was indicated for patients with benign disease or malignant disease with invasion limited to the submucosal layer. The subjects consisted of 14 cases with submucosal tumor invasion diagnosed preoperative, three with submucosal invasion clarified by endoscopic polypectomy, three with adenomas larger than 2 cm in diameter strongly suspected of being focal submucosal tumor invasion considered unsuitable for endoscopic mucosal resection and one with Crohn's disease with ileus. Two cases in whom laparoscopic surgery was not appropriate were included in this series. In one case with a superficial elevated lesion (Ma type), 15 mm in diameter, a diagnosis of moderately differentiated adenocarcinoma of the cecum was made preoperatively, but subserosal tumor invasion of the colonic wall with negative lymph node metastasis (nO) was revealed by examination of the resected specimen. The histology of the second superficial elevated lesion (Ha+lie type), which had a central depression, 13 mm in diameter and located above Bauhin's valve, was a well differentiated adenocarcinoma of which the cancerous portion invaded the proper muscle with positive lymph node metastasis (n1). Complications occurred in four cases. There were two cases of intraoperative vascular injury necessitating conversion to a standard laparotomy. One case with complete transection of the left ureter by End-GIA later underwent reoperation. The other case with minor leakage at the anastomotic site was managed with conservative therapy. In both of these cases the depth of tumor invasion had been incorrectly assessed as representing small elevated lesions, 15 mm in diameter, in the right colon. Furthermore, the cases who experienced complications had left colonic lesions. These results suggest that preoperative ultrasonic-endoscopy should be conducted as extensively as possible and that a good bloodless visual field appears to be necessary to avoid injuring adjacent organs.     

Mucosal Spreading Depressed Type Colorectal Tumors: A Report of Two Cases

Abstract: Superficial depressed type colorectal carcinomas usually show invasion into the submucosa while the tumor is small, measuring less than 10 mm in diameter. We experienced two rare cases of superficial depressed type colorectal tumors of more than 15 mm in diameter which only displayed intramucosal spread. These two lesions showed a clearly depressed appearance on colonoscopy and in the resected specimens, which were different from creeping tumors. One of the lesions was histologically diagnosed as being well differentiated adenocarcinoma without submucosal invasion, and the other was an adenoma with severe atypia. Both lesions had no Ki-ras point mutation and this result was consistent with recent genetic studies on depressed type colorectal tumor. Based on these colonoscopic findings, a simple change in the quantity of air inside the lumen may effectively distinguish a depressed type tumor larger than 15 mm, which is limited to the mucosa, from one with submucosal invasion. Thus bowel resection can be avoided in such cases.     

Present Status of Early Colorectal Cancer in Japan

We examined and clinicopathologically analyzed 422 patients with early colorectal cancer that we encountered, and discussed the problems typical of early colorectal cancers in Japan. In Japan we define early colorectal cancer as consisting of intramucosal cancer and cancer with submucosal invasion. Because histopathologists subjectively diagnose patients with intramucosal cancer, their diagnoses for the same specimen often differ from each other. The only way to avoid such confusion caused by diagnostic differences and to reach a consensus on the diagnosis of intramucosal cancer is to make a diagnosis of intramucosal cancer only in those patients who clearly show the structural atypia and/or the cellular atypia, that are typical of cancer. No one will deny the importance of the depressed type early cancer, the number of cases of which have recently been increasing in Japan. However, it is also important to assert that endoscopically-discovered depressed neoplastic lesions are not always cancer. In the depressed neoplastic lesions discovered in our patients, the number of adenoma was almost three times that of cancer. Forty percent of the patients with depressed type early cancer also had an adenoma component. Therefore, at this moment we cannot conclude that early cancer with a depression is de-novo-genetic colorectal cancer. Eighty percent of early colorectal cancers are discovered to be the protruded type of early cancer. Twenty-six percent of early cancers with submucosal invasion, including early cancers with massively submucosal invasion, are 6 to 10 mm in diameter and 76% of these are protruded early cancers. These facts indicate that colorectal tumors, protruded or depressed, which are more than 6 to 10 mm in diameter should be endoscopically removed to prevent them from becoming advanced cancers.     

Clinicopathologic evaluation of the trend toward histologically poor differentiation with submucosal invasion in superficial early colorectal adenocarcinomas

We examined differences in the degree of differentiation in intramucosal and submucosal areas of involvement in early colorectal adenocarcinomas of 131 patients and compared these findings with tumor morphology. In addition, K-ras and p53 protein expression was determined in cases where poorly differentiated adenocarcinoma was detected in the submucosa. We identified 6 patients with both intramucosal differentiated (well-to-moderately differentiated) adenocarcinoma and submucosal poorly differentiated adenocarcinoma (MwSp). The morphological tumor type was superficial in all MwSp cases. The observed MwSp adenocarcinomas had a significantly higher frequency of lymphatic invasion than the more common superficial type of adenocarcinoma. Genetic analysis of these MwSp lesions was carried out using the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method to detect the presence of K-ras codon 12 point mutations, and an immunologic staining technique was used to identify the presence of p53 protein overexpression. The K-ras mutation rate was 33.3%, and the p53 overexpression rate was 66.7% for the MwSp adenocarcinomas. Our findings suggest that the rapidly reduced histologic differentiation observed in some of these superficial colorectal adenocarcinomas may play a role in their higher degree of invasiveness. Received: November 17, 1999 / Accepted: July 7, 2000     

Clinicopathological Study on Flat and Depressed Minute Colorecta Carcinomas

Abstract: Over the last two years, a total colonoscopy was performed on 3,006 patients and 232 colorectal carcinomas were detected in these patients. Seventy one (30.6%) of the carcinomas were found to be early cancers. Eighteen (25.4%) of these 71 early cancers were minute (>5 mm) colorectal carcinomas of the flat or depressed type and they were resected endoscopically. More than half of them were accompanied by colonic polyps. Among the characteristic endoscopic features of flat and depressed early colorectal carcinomas are redness, fine granularity and defects of the innominate groove on the lesional surface. Another important finding is whitish annular mucosa surrounding the lesion. The gross appearance of these lesions was depression (3 lesions), depression with a marginal elevation (11 lesions), or flat (4 lesions). On histological examination, all the lesions were found to be well–differentiated intramucosal adenocarcinoma. It appears that depressed lesions with or without marginal elevation have a tendency to horizontal and vertical invasion, respectively. Moreover, it is thought that flat lesions are very early cancers that might later develop into depressed lesions with or without marginal elevation, or flat elevated lesions.     

Endoscopic mucosal resection for early adenocarcinoma arising in Barrett's esophagus

A 58‐year‐old man was diagnosed to have an esophageal adenocarcinoma arising in Barrett's esophagus by screening examination at the previous hospital. Endoscopically, a slightly reddish elevated lesion with a central depressed component was detected in the Barrett's epithelium. Endoscopic ultrasonography showed the thickness of the second layer of the esophagus and no enlarged lymph node. Histological examination of a biopsy specimen revealed well or moderately differentiated adenocarcinoma. From these findings, the lesion was diagnosed as a mucosal esophageal cancer, type IIa + IIc, arising in Barrett's esophagus. As he refused operation, the lesion was resected endoscopically with his informed consent. Histologically, the resected specimens showed moderately differentiated adenocarcinoma arising in Barrett's esophagus. The adenocarcinoma had invaded the superficial muscularis mucosa, but was limited to the deep one with no vessel invasion. Barrett's esophagus often has a double muscularis mucosa. Connective tissues containing vascular and lymphatic vessels exist between them. However, one consideration is whether the existence of vessels between the double muscularis mucosa and the presence of vessel invasion are risk factors for metastasis. In order for a definitive indication for endoscopic mucosal resection, the frequency of lymph node and distant metastasis in cases of early Barrett's cancer needs to be investigated.     

Depressed Type Mucosal Cancer of Large Intestine with Converging Mucosal Folds —Report of a Case—

Abstract: A case of depressed type mucosal cancer of the large intestine with converging mucosal folds is discussed. A 71-year-old female was admitted to our hospital with melena. A total colonoscopy revealed a type IIa + IIc lesion measuring 1. 5cm in diameter with converging mucosal folds in the transverse colon. An endoscopic biopsy revealed an adenocarcinoma. A diagnosis of submucosal carcinoma was made and a partial colectomy was performed. The resected specimen showed a type IIc + IIa cancer. Histologically, a well differentiated adenocarcinoma which was limited to the mucosa in association with fibrosis in the submucosa was revealed. The submucosal fibrosis was thought to be a cause of the converging mucosal folds.     

Endoscopic mucosal resection for treatment of early gastric cancer

BACKGROUND: In Japan, endoscopic mucosal resection (EMR) is accepted as a treatment option for cases of early gastric cancer (EGC) where the probability of lymph node metastasis is low. The results of EMR for EGC at the National Cancer Center Hospital, Tokyo, over a 11 year period are presented. METHODS: EMR was applied to patients with early cancers up to 30 mm in diameter that were of a well or moderately histologically differentiated type, and were superficially elevated and/or depressed (types I, IIa, and IIc) but without ulceration or definite signs of submucosal invasion. The resected specimens were carefully examined by serial sections at 2 mm intervals, and if histopathology revealed submucosal invasion and/or vessel involvement or if the resection margin was not clear, surgery was recommended. RESULTS: Four hundred and seventy nine cancers in 445 patients were treated by EMR from 1987 to 1998 but submucosal invasion was found on subsequent pathological examination in 74 tumours. Sixty nine percent of intramucosal cancers (278/405) were resected with a clear margin. Of 127 cancers without "complete resection", 14 underwent an additional operation and nine were treated endoscopically; the remainder had intensive follow up. Local recurrence in the stomach occurred in 17 lesions followed conservatively, in one lesion treated endoscopically, and in five lesions with complete resection. All tumours were diagnosed by follow up endoscopy and subsequently treated by surgery. There were no gastric cancer related deaths during a median follow up period of 38 months (3-120 months). Bleeding and perforation (5%) were two major complications of EMR but there were no treatment related deaths. CONCLUSION: In our experience, EMR allows us to perform less invasive treatment without sacrificing the possibility of cure.     

性别与结直肠癌发病特点关系的分析

[目的]分析性别与结直肠癌临床特点的关系.[方法]收集2001-10-2011-10期间在华北地区6家医院检出结直肠癌患者资料,分析性别与发病年龄、肿瘤发生部位、腺癌分化程度的关系.[结果]2450例结直肠癌患者中男性1377例,女性1073例.男∶女为1.28∶1.00;女性发病率升高.右半结肠癌比例升高.性别与结直肠癌发生年龄、发生部位、腺癌分化程度均无明显的相关性(P＞0.05).[结论]结直肠癌发病率呈上升趋势,女性大肠癌患者比例有增加趋势.筛查是结直肠癌早诊早治的关键,筛查的起始年龄应按筛查目标确定.结直肠癌发病部位应重视右半结肠发病率升高现象,全结肠镜检查为首选.     

Desmoplastic response in biopsy specimens of early colorectal carcinoma is predictive of deep submucosal invasion

PURPOSE: The aim of this study was to evaluate the role of histopathology of biopsy specimens in predicting depth of infiltration in early colorectal carcinomas before treatment. METHODS: Early colorectal carcinomas that had been resected surgically or endoscopically between 1984 and 1995 were analyzed. Histopathologic findings, including differentiation of adenocarcinoma and a desmoplastic response were investigated. RESULTS: One hundred nine early colorectal carcinomas consisted of 73 lesions of carcinomain situ, 13 submucosal carcinomas with minimum invasion, 8 lesions with moderate invasion, and 15 lesions with deep invasion. Of 73 carcinomain situ lesions, 72 (approximately 99 percent) showed well-differentiated adenocarcinomas and no desmoplastic response. Twelve (92 percent) of 13 submucosal carcinomas with minimum invasion also revealed well-differentiated adenocarcinoma without a desmoplastic response. Sixty-three percent (5/8)of lesions with moderate invasion revealed well-differentiated adenocarcinoma. None of the lesions had a desmoplastic response. Among lesions with deep invasion, 73 percent (11/15) demonstrated moderately differentiated adenocarcinoma, and 11 lesions had a prominent desmoplastic response (73 percent;P<0.01). CONCLUSIONS: These results suggest that if histopathologic findings of biopsy specimens taken from them before treatment demonstrated adenocarcinoma associated with a desmoplastic response, the lesions had at least deep invasion carcinomas. These lesions should be resected surgically. Submucosal carcinomas with minimum invasion, which have no desmoplastic response, could be treated endoscopically.     

Characteristics of early colorectal carcinoma with lymph node metastatic disease

BACKGROUND/AIMS: Endoscopic resection may safely and effectively remove early colorectal cancers. However, additional surgical treatment is needed in cases with metastatic lymph nodes for curative treatment. The purpose of this study was to investigate the correlation between lymph node metastasis and various pathological parameters in early colorectal cancers. METHODOLOGY: The clinicopathological records of 3,557 colorectal adenocarcinoma patients who underwent surgical resection at the Samsung Medical Center from August 1995 to June 2005 were reviewed. One hundred forty seven tissue samples with early colorectal cancer were used in this study. Various parameters were studied including gender, location, macroscopic appearance, differentiation, lymphatic tumor emboli, and the depth of tumor invasion. RESULTS: Twenty five patients (17.0%) had lymph node metastasis. Male gender, left colon, macroscopically depressed lesions, moderately or poorly differentiated carcinoma, depth of tumor invasion (Sm2 or Sm3), and presence of lymphatic tumor emboli were the risk factors for lymph node metastasis. CONCLUSIONS: Early colorectal cancers with male gender, location in the left colon, macroscopically depressed lesion, moderate or poor differentiation, depth in Sm2 or Sm3, and the presence of lymphatic tumor emboli have higher risk of lymph node metastasis than those without. The early colorectal cancers with these risk factors should have surgical resection.     

Minute Depressed-Type Submucosal Invasive Cancer–5 mm in Diameter with Intermediate Lymph-Node Metastasis: Report of a Case

We report a rare case of colon cancer in which a depressed-type tumor only 5 mm in diameter invaded the submucosal layer and produced intermediate lymph node metastasis. A 47-year-old male received a total colonoscopy for a depressed-type lesion with marginal elevation in the sigmoid colon. The lesion measured 5 mm in diameter. On chromoendoscopic examination, the depression was clearly demarcated and an irregular pit pattern was identified in the demarcated area by magnification suggesting invasion of the submucosal layer requiring surgery. Laparoscopic-assisted sigmoidectomy was performed and the resected specimen demonstrated well-differentiated adenocarcinoma. The depth of invasion was only 900 μm. There was no lymphovascular invasion although not only paracolic, but also intermediate lymph node metastasis was detected. There have been some reports about small depressed-type colorectal cancer invading the submucosal layer; however, intermediate LN metastasis is very rare in submucosal colorectal cancer. In this case, there were two noteworthy points: 1) despite the small size, submucosal invasion could be estimated preoperatively, therefore, a successful lymph node dissection was performed by laparoscopic surgery; and 2) although this depressed-type cancer invaded the submucosal layer only 900 μm and there was no lymphovascular invasion, intermediate lymph node metastasis was detected. Reprints are not available.     

Retrospective radiographic analysis of nonpedunculated colorectal carcinomas with special reference to tumor doubling time and morphological change

OBJECTIVE: Our aim was to characterize the development of nonpedunculated colorectal carcinomas by retrospective radiographic analysis, with special reference to tumor doubling time and morphological change. METHODS: Eleven colorectal carcinomas, which were observed for >6 months by barium enema examinations, were collected and retrospectively reviewed. There were five early and six advanced carcinomas, including submucosally invasive, superficial depressed carcinomas. RESULTS: Mean diameter of lesions at initial barium enema examination was 13.5 mm (early, 10.4 mm; advanced, 16.0 mm) and that at final barium enema examination was 30.9 mm (early, 18.2 mm; advanced, 41.5 mm). Initial morphology of the lesions was superficial in three, sessile in seven, and semipedunculated in 1. There was no pedunculated lesion. Macroscopic morphology of the five early carcinomas was superficial depressed (IIc) in two cases, mostly depressed but partly elevated (IIc+IIa) in one case, and superficial elevated with a depressed component (IIa+IIc) in two cases; all of the advanced carcinomas were of the ulcerated type. Mean doubling time was 6.8 months (early, 9.4 months; advanced, 4.7 months). Early carcinomas had significantly longer doubling times than advanced carcinomas (p = 0.017, Wilcoxon's text). The lesions with the longest doubling times were superficial depressed lesions. CONCLUSIONS: Early carcinomas have longer doubling times than advanced carcinomas. Most nonpedunculated colorectal carcinomas grow without significant morphological changes. Superficial depressed type tumors grow slowly, maintaining their macroscopic morphology.     

Long-term outcome of endoscopic semiconductive diode laser irradiation therapy with injection of indocyanine green for early gastric cancer

Background and Aim:  Semiconductive laser irradiation has been used to treat early gastric cancer. However, the long-term follow up results have not been reported. The objective of the present study was to assess retrospectively the clinical usefulness of diode laser irradiation for early gastric cancer.
Methods:  The subjects of this study were 13 patients (14 lesions) selected from 125 patients with early gastric cancer who were treated by endoscopy during the period from September 1995 to February 2003. The macroscopic tumor type was superficial type, including eight lesions of 0'–IIc and six lesions of 0'–IIa. Histological diagnoses were eight cases (nine lesions) of well-differentiated adenocarcinoma, three cases of moderately differentiated adenocarcinoma and two cases of poorly differentiated adenocarcinoma. After injection with indocyanine green solution (1 mg/mL) into the submucosal layer, a semiconductive diode laser (30–40 W/s) was irradiated by the non-contacting method.
Results:  The total amount of laser irradiation for 14 lesions was 9568.80 ± 7197.01 J on average. There was no major complication. In the period up to December 2007, six patients survived and seven patients died. However, no-one died of progression of gastric cancer. The mean survival times of all patients, survivors and patients who died were 5 years 2.8 months; 6 years 4.5 months; and 4 years 11.7 months, respectively.
Conclusions:  Early gastric cancer can be successfully treated by laser therapy with few complications and good prognosis. This method is expected to be most suitable and effective for elderly patients with serious underlying disease.     

Size does not determine the grade of malignancy of early invasive colorectal cancer

AIM： To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers （EI-CRCs）, and to determine whether malignancy grade depends on size. METHODS： A total of 583 consecutive EI-CRCs treated by endoscopic mucosal resection or surgery at the National Cancer Center Hospital between 1980 and 2004 were enrolled in this study. Lesions were classified into two groups based on size： small （≤10 ram） and large （〉10 ram）. Clinicopathological features, incidence of lymph node metastasis （LNM） and risk factors for LNM, such as depth of invasion, lymphovascular invasion （LVI） and poorly differentiated adenocarcinoma （PDA） were analyzed in all resected specimens. RESULTS： There were 120 （21%） small and 463 （79%） large lesions. Histopathological analysis of the small lesion group revealed submucosal deep cancer （sin： 1〉1000 μm） in 90 （75%） cases, LVI in 26 （22%） cases, and PDA in 12 （10%） cases. Similarly, the large lesion group exhibited submucosal deep cancer in 380 （82%） cases, LVI in 125 （27%） cases, and PDA in 79 （17%） cases. The rate of LNM was 11.2% and 12.1% in the small and large lesion groups, respectively.CONCLUSION： Small EI-CRC demonstrated the same aggressiveness and malignant potential as large cancer.     

Cellular and Structural Atypia of the Early Colorectal Cancers

Cellular and structural gland atypia in lesions of early colorectal cancer removed by endoscopic polypectomy in 101 patients were histopathologically studied. The following results were observed. Cellular atypia was frequently found in lesions with a high rate of nuclear polarity loss and multiple nuclear mitoses (99. 0%). The most frequent findings in the glands with structural atypia was intraglandular glands and crowding of neoplastic glands (85. 1%). Most of the appearances of the cellular and structural atypias showed no marked relationship with the sizes of the lesions, depth of invasion and association of adenoma components. Early cancer had both cellular and structural atypia in 95% of the patients and could be diagnosed by conventional histopathological criteria. However five patients with early cancer showed no structural atypia and were diagnosed as having cellular atypia. These cancers were early intramucosal cancer and four lesions were associated with adenoma components 20 mm or less in size. The loss of nuclear polarity and nuclear pleomorphism may be considered more important than nuclear stratification and mitoses in the diagnosis of early cancer.     

内镜下黏膜染色联合黏膜切除对大肠侧向发育肿瘤的诊断治疗

目的 探讨普通电子肠镜下靛胭脂黏膜染色联合黏膜切除对大肠侧向发育型肿瘤及早期大肠癌的临床诊治价值。方法 对3860例肠镜检查中发现的肠腔黏膜隆起、红斑、表面粗糙不平、血管纹理消失、肠黏膜无名沟中断等可疑黏膜病灶，行镜下喷洒0．4％靛胭脂黏膜染色，对染色发现的大肠侧向发育型肿瘤，观察病灶大小并进行形态分型，病灶黏膜可随充吸气变形者及黏膜下注射液体呈抬举征阳性者行内镜黏膜切除（EMR）21例、内镜下分片黏膜切除术（EPMR）11例、未能行黏膜切除者行活检6例，切除病灶黏膜送病理检查。结果 发现LST病灶38侧，检出率为0．98％。其中．颗粒均一型18个（46．6％）、结节混合型10个（25．9％）、平坦隆起型7个（18．1％）．假凹陷型3个（7．8％）。病变分布：直肠15个（39．5％），乙状结肠8个（21．0％），降结肠5个（13．2％），横结肠4个（10．5％），升结肠3个（7．9％）．回盲部3个（7．9％）。病理检查：38例LST病灶中早期癌5例，检出率为13．2％，进展期大肠癌2例（5．2％）．良性腺瘤31（81．6％）。结论 普通电子肠镜下对大肠黏膜可疑病灶靛胭脂染色能够有效发现大肠LST病灶，联合镜下黏膜切除对早期大肠癌诊断和防治具有较高的临床价值。