Magnifying pharmacoendoscopy: response of microvessels to epinephrine stimulation in differentiated early gastric cancers

BACKGROUND: Magnifying endoscopy is a promising modality for fine observation of minute surface structures and microvessel architecture in gastric lesions. OBJECTIVE: To observe the response of microvessels to epinephrine stimulation in early gastric cancer tissues and to assess the usefulness of magnifying pharmacoendoscopy for histologic diagnosis. DESIGN: This was a prospective pilot study. SETTING: This study was conducted at an academic hospital. PATIENTS: Twenty-nine patients with differentiated early gastric cancer were enrolled. INTERVENTIONS: Microvessels in both the cancerous lesion and its adjacent non-neoplastic gastric mucosa were observed by magnifying endoscopy before and after focal spray with epinephrine solution (0.05 mg/mL). MAIN OUTCOME MEASUREMENTS AND RESULTS: After epinephrine stimulation, noncancerous gastric mucosa surrounding the cancerous lesion showed a change in color from red to white; no microvessels were evident. On the other hand, all the cancerous lesions examined clearly showed enhancement of tumor microvessels. The rate of detection of tumor microvessels by magnifying pharmacoendoscopy (100%) was significantly higher than that by magnifying endoscopy alone (41.3%). LIMITATIONS: This was small pilot study. CONCLUSIONS: Magnifying pharmacoendoscopy with epinephrine is a powerful tool for assessing tumor vascularity and may contribute to the histologic diagnosis of differentiated early gastric cancers before endoscopic treatment.     

DETERMINING THE HORIZONTAL EXTENT OF EARLY GASTRIC CARCINOMA: TWO MODERN TECHNIQUES BASED ON DIFFERENCES IN THE MUCOSAL MICROVASCULAR ARCHITECTURE and DENSITY BETWEEN CARCINOMATOUS and NON‐CARCINOMATOUS MUCOSA

Two modern endoscopic techniques are presented with a view to determining the horizontal extent of gastric cancer. They are based on differences in the microvascular structure and density of early gastric cancer compared with those of the non‐cancerous background mucosa. One technique requires magnifying endoscopy which can identify microvascular architecture that shows the characteristic findings of carcinoma. The other technique is an image‐processing technique which enhances the differences in microvascular structure and density between carcinomatous mucosa and non‐carcinomatous mucosa. We demonstrate an example of these techniques applied to an intramucosal carcinoma of a differentiated type, the margin of which could not be determined simply by traditional endoscopy with dye spreading. Magnified observation could detect a demarcation line between the carcinoma and non‐carcinomatous mucosa. In addition, the image‐processing technique enhanced the contrast of redness between cancerous area and non‐cancerous mucosa. Both of these techniques are useful for detecting the precise extent of a carcinoma. The combined application of these techniques should be helpful in determining the precise horizontal extent of early gastric cancer.     

DIFFERENTIAL DIAGNOSIS OF GASTRIC LESIONS BY MAGNIFYING ENDOSCOPY

We performed magnifying endoscopy for patients with suspected gastric diseases. Among these patients, 67 patients with early gastric cancer and 31 benign gastric diseases were enrolled in this study. The patients with early gastric cancer included 46 differentiated tubular adenocarcinoma (33 mucosal cancer, 13 submucosal cancer) and 21 non‐differentiated tubular adenocarcinoma (12 mucosal cancer, 9 submucosal cancer). The benign gastric lesions included 23 gastric ulcer or gastric ulcer scars, three gastritis, and five gastric adenomas. Small regular patterns were observed; 39% in differentiated adenocarcinoma, 5% in undifferentiated adenocarcinoma, and 19% in benign gastric diseases. Irregular patterns were observed 37%, 52%, and 6%. Lack of visible structure was observed 18%, 90%, and 10%. Abnormal vessels were observed 26%, 81%, and 16%. Small regular patterns were observed significantly more frequently in differentiated adenocarcinoma than in undifferentiated adenocarcinoma (P < 0.001). Lack of visible structure and Irregular patterns were observed significantly more frequently in undifferentiated adenocarcinoma than in differentiated adenocarcinoma (P < 0.001). In order to spread this useful endoscopy widely easy recognition of abnormality, histological backbone, and further technical developments in hardware and software should be required.     

MAGNIFYING ENDOSCOPY FOR THE DIAGNOSIS OF EARLY GASTRIC CANCER

Magnifying endoscopy of stomach cancer requires observation of minute structure and minute vessel patterns of the mucosal surface. The small pits, various‐sized pits, irregularly branched pits and irregular vessels were found to be characteristics as the surface structure of early gastric cancer. Small pits were commonly observed on the differentiated type of early gastric cancer (88%) compared with the undifferentiated type (50%). We found it important to analyze not only the minute vessel patterns, but also the minute surface structure to ensure magnifying endoscopic observation using 0.1% indigo‐carmine and the binarized images would be effective in determining the margin of the lesion. The relationship between the findings of magnifying endoscopy in cancer and the histology should now be investigated. Applying the techniques mentioned above, more delicate observation in the regular endoscopy and prudent photographing to obtain clear images might be promoted. Thus, this would contribute to endoscopy with a concept similar to optical biopsy, and which can depend on the usual biopsy methods.     

MAGNIFYING ENDOSCOPY WITH NARROW BAND IMAGING FOR EARLY DIFFERENTIATED GASTRIC ADENOCARCINOMA

We have been using magnifying endoscopy with narrow band imaging (NBI) to study early differentiated gastric adenocarcinomas and to assess the relationship between microvessel pattern, pit pattern and histological pattern. The magnified view of the cancerous area showed three types of pattern: (i) a mesh pattern, consisting of mesh‐like connected microvessels; (ii) a loop pattern, consisting of loop‐like microvessels that were not connected and had tubule‐like or villus‐like mucosal structures along them; and (iii) an interrupted pattern, consisting of interrupted thick or thin vessels without mucosal structures. The mesh type of microvascular pattern showed a round pit pattern in 88.9% of cases (32/36) and the loop type of microvascular pattern showed a non‐round pit pattern in 100% of cases. Among lesions that showed a mesh pattern or a loop pattern, 94.9% (56/59) were mucosal cancer and 5.1% (3/59) were submucosal cancer. However, 92.3% (12/13) of lesions that showed an interrupted pattern were submucosal differentiated adenocarcinoma and 7.7% (1/13) were mucosal differentiated adenocarcinoma. The present findings provide basic data on the characteristics of mucosal differentiated gastric adenocarcinoma revealed by magnifying endoscopy with NBI, as well as invasive changes such as submucosal invasion.     

放大内镜联合端粒酶逆转录酶对胃癌前病变的诊断价值

目的探讨放大内镜和人端粒酶逆转录酶（hTERT）在胃黏膜癌前病变中的诊断价值。方法应用放大内镜对154例病人进行检查,放大内镜下做出实时诊断,取活组织分别送病理学检查和实时荧光定量PCR检测hTERTmRNA的表达。放大内镜下胃小凹分为A、B、C、D、E5型。A型：圆点状小凹;B型：线状小凹;C型：稀疏而粗大的线状小凹;D型：斑块状;E型：绒毛状。结果放大内镜下B—E4种胃小凹形态肠上皮化生发生率差异有统计学意义（X^2=17．58,P〈0．05）,并且肠上皮化生的严重程度逐渐加重（Pearson列联系数=0．531,P〈0．05）;C—E3种胃小凹形态与不典型增生的严重程度关系密切（X^2=10．256,Pearson列联系数=0．549,P〈0．05）;B、C、D、E4型胃小凹形态间hTERT mRNA表达量差异有统计学意义（F=3．274,P〈0．05）。若以胃癌中hTERT mRNA表达量作为胃癌的诊断标准,病理未诊断为胃癌而放大内镜下表现为E型胃小凹的病人中65％符合该标准。结论放大内镜下胃黏膜微细结构形态可反映病变程度的轻重;hTERT是一重要的胃癌标志物,随访E型胃小凹和高hTERT表达的患者有助于早期发现胃癌。     

Study on minute surface structures of the depressed‐type early gastric cancer with magnifying endoscopy

Background: Gastric surface patterns and morphology of minute surface vessels in depressed lesions were analyzed using a magnifying endoscope with high resolving power to contribute to qualitative diagnosis of gastric cancer. Methods: Subjects were diagnosed with depressed‐type early gastric cancer (pT1), there were 63 lesions, 38 differentiated‐type lesions, and 25 undifferentiated‐type lesions. There were also 40 benign depressed lesions found. After routine observations with an endoscope, amplifying observations of lesions were made by EG‐410CR (Fuji Photo Optical; Saitama, Japan) (CR). The images were compared with macroscopic patterns and histopathological patterns of the surgical specimens and endoscopic mucosal resection specimens. Results: Surface patterns of gastric depressed lesions were classified as irregular protrusion, normal papilla, pseudopapilla and amorphia. Irregular protrusion was found only in cancerous lesions. Characteristic minute vessels were observed in amorphia. Their patterns were classified into the following six types: sand, fence, round net, flat net, branch and coil. Irregular protrusion and minute vessels in amorphia (round net, flat net, branch and coil) were specific to cancers. There was a tendency for round net and flat net patterns to be found often in differentiated cancers and for branch and coil patterns to be found often in undifferentiated cancers. Conclusion: This magnifying endoscopic classification is considered useful for the qualitative diagnosis of depressed‐type early gastric cancer.     

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR EARLY GASTRIC CANCER USING MAGNIFYING ENDOSCOPY WITH A COMBINATION OF NARROW BAND IMAGING AND ACETIC ACID INSTILLATION

Demarcation of early gastric cancers is sometimes unclear. Enhanced‐magnification endoscopy with acetic acid instillation and magnifying endoscopy with a narrow band imaging (NBI) system have been useful for recognition of demarcation of early gastric cancers. We report a patient with early gastric cancer who underwent a successful endoscopic submucosal dissection (ESD) by magnifying endoscopy with the combined use of NBI and acetic acid instillation. A 72‐year‐old man with early gastric cancer underwent ESD. Demarcation of the lesion was not clear, but magnifying endoscopy using the combination of NBI and acetic acid clearly revealed the demarcation. ESD was carried out after spots were marked circumferentially. We identified the positional relation between the demarcation and all markings. Resection of the lesion was on the outside of the markings. Histopathologically, the lesion was diagnosed as a well‐differentiated adenocarcinoma limited to the mucosa. The margins were carcinoma free. Magnifying endoscopy combining the use of NBI with acetic acid instillation is simple and helpful for identifying the demarcation of early gastric cancer. This method may be useful in increasing the rate of complete resection by ESD for early gastric cancer.     

Hemoglobin content in intramucosal gastric carcinoma as a marker of histologic differentiation: a clinical application of quantitative electronic endoscopy

BACKGROUND: It has been suggested that the endoscopic color of intramucosal gastric carcinoma is correlated with mucosal vascularity within the carcinomatous tissue. The development of electronic endoscopy has made it possible to quantitatively measure the mucosal hemoglobin volume, using a hemoglobin index. The aims of the present study were to investigate whether this hemoglobin index is useful for evaluating the change in color of early gastric carcinoma and to verify the diagnostic value of this index for distinguishing between histologic degrees of differentiation. METHODS: The ratios of the hemoglobin index of cancerous and non-cancerous mucosa for 26 differentiated and 18 undifferentiated intramucosal gastric carcinomas were determined from electronic endoscopic imaging data. RESULTS: The mean ratio of the hemoglobin index of cancerous and non-cancerous mucosa in the differentiated gastric carcinomas was higher than it was in the undifferentiated carcinomas (1.23: 95% CI [1.15, 1.31] versus 0.84: 95% CI [0.81, 0. 88]). The sensitivity and specificity for discriminating undifferentiated from differentiated carcinoma were 100% and 85%, respectively. CONCLUSION: Measurement of mucosal hemoglobin volume (hemoglobin index) is useful for evaluating the endoscopic color of early gastric carcinoma quantitatively and may be helpful in distinguishing differentiated from undifferentiated carcinoma.     

Predicting histologic findings from endoscopic appearance of early gastric cancer.

In 156 cases of depressed early gastric cancer in the antrum or corpus, the differences between differentiated and undifferentiated carcinoma were studied by comparing the histological diagnosis of the resected specimens and their endoscopic appearance. We reached the following conclusions: (a) Younger patients more often had undifferentiated carcinoma (mean age: 59.8 years) than differentiated carcinoma (mean age: 77.2 years). (b) One hundred and twenty-five of 156 cases were limited to the mucosa and 29 cases were limited to the submucosa. (c) Undifferentiated gastric cancers more often invaded beyond the mucosa even when the tumor was small than did differentiated tumors. (d) Many differentiated tumors showed a smooth depressed surface, erythema at the edge of the cancer, and tapering of the gastric rugae. (e) In undifferentiated lesions the depressed tumor surface had a varied appearance, with various sized granules and nodules, as well as fading of the mucosal color and fusion of the rugae. It is important at endoscopy to consider not only whether a lesion is benign or a malignant, but also to consider its histological type. In particular, it is vital to detect small, undifferentiated gastric cancers as early as possible.     

Confocal endomicroscopy for in vivo detection of microvascular architecture in normal and malignant lesions of upper gastrointestinal tract

Background and Aim: Confocal laser endomicroscopy allows subsurface analysis of gastrointestinal mucosa during ongoing endoscopy. The present study assessed the feasibility of in vivo detecting superficial vascular architecture by confocal endomicroscopy in normal upper gastrointestinal mucosa and malignant lesions. Methods: Early gastric cancer in eight patients, superficial esophageal carcinoma in six patients, and asymptomatic normal control in 10 patients were studied by confocal endomicroscopy. The characteristic of endomicroscopic microvascular architecture from normal and malignant mucosa was described and images were evaluated. Results: Confocal endomicroscopy enabled clear visualization of the vascular networks of gastroesophageal mucosa. Honeycomb‐like and coil‐shaped regular microvascular architecture surrounding gastric pits were visible in the normal gastric body and antrum, respectively. Differentiated gastric cancerous mucosa showed hypervascularity and various caliber microvessels with irregular shapes. Undifferentiated gastric cancers disclosed a hypovascularity and irregular short branch vessels. Normal squamous epithelium had regular intraepithelial papillary capillary loops (IPCLs) directed toward the luminal surface. In superficial esophageal squamous carcinoma, dilated IPCLs were visible at the upper layer of the squamous mucosa. In esophageal adenocarcinoma, abnormal microvascular architecture showed tortuous and various calibers blood vessels. Of all the images, 41% were graded as good quality. The mean kappa value for interobserver agreement for the prediction of cancerous mucosa was 0.792. Conclusions: Confocal laser endomicroscopy system could yield very clear images of superficial microvascular network in the gastroesophageal mucosal layer both in malignant and normal mucosa. Endomicroscopic observation of vascular architecture may be of assistance in the identification of early gastroesophageal cancers.     

NEWLY DEVELOPED OPTIMAL BAND IMAGING SYSTEM FOR THE DIAGNOSIS OF EARLY GASTRIC CANCER

Background: Magnifying narrow band imaging system is useful for the diagnosis of early gastric cancer. However, it is difficult for the operator of the scope to maintain the correct distance between the tip of the endoscope and the gastric mucosa for appropriate visualization. The newly developed optimal band imaging system can reconstruct good spectral images derived from ordinary endoscopic images and enhance the mucosal surface without magnification as well as with low magnification. This imaging technique is based on narrowing the bandwidth of the conventional image arithmetically, using spectral estimation technology. Methods: We evaluated endoscopic features of 30 lesions with elevated‐type, 32 lesions with depressed‐type and two lesions with flat‐type early gastric cancer using this new system. Results: We found the best images in all cases of early gastric cancers by using a specific combination of the following three wavelengths available in this system: 470 nm for blue, 500 nm for green and 550 nm for red. The optimal band images showed the depressed‐type early gastric cancer as reddish lesions distinct from the surrounding yellowish non‐cancerous area, leading to a clear demarcation line between the cancerous and non‐cancerous mucosa without magnification. Moreover, 30–40‐fold magnified optimal band images showed a clearly irregular microvascular pattern or a microstructure pattern of the mucosal surface in all types of gastric cancers. Conclusion: This new system can provide useful information for diagnosing various types of early gastric cancers without and with low magnification.     

The study of dynamic chemical magnifying endoscopy in gastric neoplasia

BACKGROUND: We assessed the usefulness of acetic acid-enhanced magnifying endoscopy in the diagnosis of gastric neoplasia. METHODS: Forty-five patients (27 men, 18 women; median age 61.6 years) with gastric carcinoma or adenoma were enrolled in a prospective trial of enhanced magnifying endoscopy after instillation of 1.5% acetic acid. Acetic acid-enhanced magnified views of carcinoma or adenoma and the surrounding non-neoplastic mucosa were observed, and the duration of whitening time of each lesion was recorded. OBSERVATIONS: Magnified views of carcinoma showed a minute, grain-like pattern that differed from the surrounding noncancerous mucosa. The histopathologic diagnostic criteria were based on the Vienna classification of GI epithelial neoplasia. The mean duration of whitening differed with each histologic type: low-grade adenoma, 94 seconds; high-grade adenoma, 24.3 seconds; noninvasive carcinoma, 20.1 seconds; invasive intramucosal carcinoma, 3.5 seconds; and submucosal carcinoma or beyond, 2.5 seconds. The duration in the non-neoplastic surrounding mucosa was 90 seconds. After the disappearance of whitening in the carcinoma, the irregular pattern of the carcinoma reappeared, and the contrast between carcinomatous microvessels and the whitened non-neoplastic tissue became very clear on magnifying endoscopy. In accordance with the duration of whitening, more than 1 minute was termed "continuous whitening," from 31 to 60 seconds was "delayed disappearance of whitening," from 30 to 6 seconds was "early disappearance of whitening," and 0 to 5 seconds was "no response." CONCLUSIONS: Acetic acid-enhanced magnifying endoscopy was useful for the diagnosis of gastric adenocarcinoma. The duration of whitening differed among grades of neoplasia, and it was possible to observe changes in the whitening with time. Acetic acid-enhanced magnifying endoscopy, therefore, can be termed "dynamic chemical magnifying endoscopy."     

Diagnosis of depressed‐type early gastric cancer using small‐caliber endoscopy with flexible spectral imaging color enhancement

Background and Aim: Small‐caliber endoscopy has lower resolution than normal‐caliber endoscopy, limiting its use in routine outpatient practice. Flexible spectral imaging color enhancement (FICE) strengthens the color contrast of depressed‐type early gastric cancer without magnification. The aim of the present study was to evaluate the detection of depressed‐type early gastric cancer using small‐caliber endoscopy with the FICE system. Methods: Eighty‐two patients diagnosed with depressed‐type early gastric cancer by standard endoscopy and biopsy were evaluated by small‐caliber endoscopy. FICE images and conventional images were compared. Color differences in all 82 lesions were measured between malignant lesions and the surrounding mucosa using the Commission Internationale de L'Eclairage (CIE) 1976 color space. Results: Most cancers were readily detected as reddish lesions on FICE images. Lines of demarcation between the malignant lesion and the surrounding mucosa were easily identified with FICE images, as such cancers could be clearly distinguished from the surrounding atrophic mucosa. Greater median color differences between malignant lesions and the surrounding mucosa were present in FICE images compared with conventional images, resulting in images with better contrast (27.2 vs 18.7, P < 0.0001). Conclusions: Small‐caliber endoscopy with the FICE system provides better color contrast of depressed‐type early gastric cancers than conventional small‐caliber endoscopy, and the FICE system may facilitate the diagnosis of this type of cancer as a new endoscopic modality.     

Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer

BACKGROUND: The color change observed endoscopically in early gastric cancer is thought to correlate with vascular density and architecture. This study investigated the endoscopic microvascular architecture in intramucosal gastric carcinoma in vivo. METHODS: Intramucosal gastric carcinomas without ulceration in 27 patients were studied by using a new magnifying upper endoscope with attention to microvascular findings. The carcinomas were divided into two major types histologically: differentiated (18) and undifferentiated (9). RESULTS: A regular subepithelial capillary network was demonstrated in noncancerous mucosa. The appearance of the carcinomas differed depending on histologic differentiation. With all of the differentiated carcinomas, there was a well-demarcated area where the regular capillary pattern of noncancerous mucosa had disappeared and irregular microvessels were proliferating. In contrast, with undifferentiated carcinomas there was only an ill-defined area with disappearance or a reduction in the density of capillaries in the noncancerous mucosa. CONCLUSIONS: Magnified endoscopic observation of microvessels may be of assistance in the identification of intramucosal gastric carcinomas that exhibit only subtle changes in color and shape at standard endoscopy.     

Value of Magnifying Endoscopy With Narrow-Band Imaging and Confocal Laser Endomicroscopy in Detecting Gastric Cancerous Lesions

Although the respective potentials of magnifying endoscopy with narrow-band imaging (ME-NBI) and confocal laser endomicroscopy (CLE) in predicting gastric cancer has been well documented, there is a lack of studies in comparing the value and diagnostic strategy of these 2 modalities. Our primary aim is to investigate whether CLE is superior to ME-NBI for differentiation between gastric cancerous and noncancerous lesions. A secondary aim is to propose an applicable clinical strategy.We conducted a diagnostic accuracy study involving patients with suspected gastric superficial cancerous lesions. White light endoscopy, ME-NBI, and CLE were performed diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value between ME-NBI and CLE were assessed, as well as agreements between ME-NBI/CLE and histopathology.This study involved 86 gastric lesions in 82 consecutive patients who underwent white light endoscopy, ME-NBI, and CLE before biopsy. The accuracy, sensitivity, and specificity for ME-NBI were 93.75%, 91.67%, and 95.45%, compared with 91.86%, 90%, and 93.48%, respectively, for CLE, for discrimination cancerous/noncancerous lesion (all P > 0.05). For undifferentiated/differentiated adenocarcinoma, CLE had a numerically but not statistically significantly higher accuracy than ME-NBI (81.25% vs 73.33%, P = 0.46). Agreements between ME-NBI/CLE and histopathology were near perfect (ME-NBI, κ = 0.87; CLE, κ = 0.84).CLE is not superior to ME-NBI for discriminating gastric cancerous from noncancerous lesions. Endoscopist could make an optimal choice according to the specific indication and advantages of ME-NBI and CLE in daily practices.     

STUDY OF THE TUMOR VESSELS IN DEPRESSED‐TYPE EARLY GASTRIC CANCERS USING NARROW BAND IMAGING MAGNIFYING ENDOSCOPY AND CDNA ARRAY ANALYSIS

Background: Since endoscopic mucosal resection has been applied to differentiated gastric cancers with invasion limited to the mucosal layer, the diagnosis of their differentiation is important. The degree of differentiation varies depending on the size and location of the tumors. Correct diagnosis by biopsy can be difficult because depressed‐type early gastric cancers sometimes contain mixed histology. Methods: Fifteen patients with depressed‐type early gastric cancers were observed by magnifying endoscopy with a narrow band lighting system. The fine mucosal vascular pattern was recorded and compared with the histological differentiation and features of vessels by staining with CD34. In some patients, cDNA array analysis was performed to determine differences among histological types. Results: Tumor vascular patterns were classified into two categories. Grid‐like network patterns not only characterized differentiated type but were also associated with high microvascular density. Short twig‐like patterns typified the undifferentiated type and a low vascular density. Differentiated types highly expressed some angiogenic factors, such as VEGFc and Flt‐4. Conclusions: Tumor vessel pattern of depressed‐type early gastric cancer obtained by narrow band imaging magnifying endoscopy reflects both the histological features and the degree of expression of angiogenic factors.     

EARLY GASTRIC CANCER: PROPOSAL FOR A NEW DIAGNOSTIC SYSTEM BASED ON MICROVASCULAR ARCHITECTURE AS VISUALIZED BY MAGNIFIED ENDOSCOPY

We have developed a magnified endoscopic technique for observing the microvascular architecture within the gastric mucosa in units as small as capillary and we have reported the characteristic findings of the microvascular architecture in both normal gastric mucosa and early gastric cancer. The findings in the normal stomach were different depending on the section of the stomach. The body mucosa demonatrated a regular honeycomb‐like subepithelial capillary network pattern with a collecting venule, while the antral mucosa demonstrated a regular coil‐shaped subepithelial capillary network pattern. The magnified endoscopic findings of early gastric carcinoma were different depending on the types of histological differentiation. The characteristic findings of differentiated carcinoma were (1) the presence of a demarcation line; (2) the disappearance of the regular subepithelial capillary network pattern; and (3) the presence of an irregular microvascular pattern. The findings of undifferentiated carcinoma showed only a reduction in or else the complete disappearance of the regular subepithelial capillary network pattern. In clinical practice, the magnified endoscopic findings of differentiated carcinoma are useful both for determining the margin of early gastric cancer and for making a differential diagnosis between gastritis and gastric cancer in the case of flat reddened lesions. The microvascular architecture as visualized by magnified endoscopy could be a new diagnostic system for the endoscopic diagnosis of early gastric cancer.     

Usefulness of magnifying endoscopy with narrow-band imaging for determining gastric tumor margin

Background and Aim: Magnifying endoscopy with narrow‐band imaging (ME‐NBI) enhances images of the irregular mucosal structures and microvessels of gastric carcinoma, and could be useful for determining the margin between cancerous and non‐cancerous mucosa. We evaluated the usefulness of ME‐NBI for determining the tumor margin compared with indigocarmine chromoendoscopy (ICC). Methods: The subjects were 110 patients (with 118 lesions) who underwent endoscopic submucosal dissection for gastric tumors. They were randomized into ME‐NBI and ICC groups. Marking was carried out by electrocautery with the tip of a high‐frequency snare at the tumor margins determined by each observation. The distance from the marking dots to the tumor margin was measured histopathologically in the resected specimens. Marking was diagnosed as accurate if the distance was less than 1 mm. Results: Of the 118 gastric lesions, 55 were allocated to the ME‐NBI group, and 63 to the ICC group. Seventeen lesions in the ME‐NBI group and 18 lesions in the ICC group were excluded because the distance from the marking dots to the tumor margin was immeasurable histopathologically. Thirty‐eight lesions in the ME‐NBI group and 45 lesions in the ICC group were evaluated. The rate of accurate marking of the ME‐NBI group was significantly higher than that of the ICC group (97.4% vs 77.8%, respectively; P‐value = 0.009). Conclusion: Magnifying endoscopy with narrow‐band imaging can identify gastric tumor margins more clearly than ICC.     

胃黏膜萎缩、肠上皮化生及异型增生的放大内镜表现及其诊断价值

目的 确定胃黏膜萎缩、肠上皮化生及异型增生的形态学特征，探讨放大内镜结合染色对上述病变诊断的可行性和准确性。方法 应用Fujinon EG485 ZH型放大内镜对100例患者进行检查及0．5％美蓝染色，在确定A、B、C、D、E 5型基本胃小凹形态的基础上，制订放大内镜的诊断分型及放大内镜对萎缩、肠上皮化生和异型增生的判定标准，与相应部位活检所获得的417个病变组织的病理组织学检查结果进行比较分析。结果 胃黏膜萎缩主要表现为胃小凹粗大而分布稀疏，肠上皮化生表现为C、D、E型小凹形态伴美蓝着色阳性，异犁增生表现为轻度凹陷、隆起或平坦性病变伴细微结构消失、细微小凹或细微结构粗糙紊乱放大内镜对萎缩诊断的敏感性、特异性分别为95．85％和95．09％；对肠上皮化生分别为88．30％和90．83％；对异型增生分别为91．52％和94．41％，均明显高于普通内镜。结论 根据放大内镜下萎缩、肠上皮化生和异型增生的形态学特征可以使内镜对上述病变诊断的准确性明显提高。