Histologic diagnosis based on forceps biopsy is not adequate for determining endoscopic treatment of gastric adenomatous lesions

Gastric high-grade dysplasia can be associated with submucosal invasion: evaluation of its prevalence in a series of 121 endoscopically resected specimens

Gastric neoplasms classified as high-grade dysplasia (HGD) by Western pathologists are frequently diagnosed as tubular adenocarcinoma in Japan. Here, we evaluated the prevalence of submucosal and lymphovascular invasion in a series of 125 endoscopically resected gastric neoplasms. On the basis of Western criteria, the lesions were classified as poorly cohesive carcinomas (n=4) (excluded from further analysis), low-grade dysplasia (n=4), pure HGD (n=78), HGD with tubular adenocarcinoma (n=4), and pure tubular adenocarcinoma (n=35). Submucosal invasion was found in 3.8% of the 78 HGDs, 75.0% of the 4 HGDs combined with adenocarcinoma, and 11.4% of the 35 adenocarcinomas. Venous invasion was detected in 1.3% of the 78 HGDs, 75% of the 4 HGDs combined with adenocarcinoma, and none of the 35 tubular adenocarcinomas. Lymphatic invasion was absent in HGD but noted in 25% of the HGDs combined with adenocarcinoma, and 2.9% of the tubular adenocarcinomas. Thus, we demonstrated that lesions characterized as HGD on the basis of Western criteria can be associated with submucosal and lymphovascular invasion. Endoscopic therapy has made it less crucial to differentiate between HGD and intramucosal adenocarcinoma in biopsy samples of small tubular neoplasms. However, it is important to recognize that the criteria for dysplasia currently used in the West may understate the degree of malignant potential. To limit any diagnostic discrepancy between biopsy, endoscopic resection, and surgical specimens, it is suggested that the features of HGD and adenocarcinoma be reevaluated, which may result in some lesions being classified as mucosal adenocarcinoma.

Endoscopic resection as a first therapy for gastric epithelial atypia: is it reasonable?

BACKGROUND AND AIMS

Gastric atypical cell (GAC), an indefinite pathologic finding, often requires repeated biopsy or other diagnostic treatments, such as endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or operation (OP). The aim of this study was to analyze the initial endoscopic and histologic findings of GAC and to discuss the necessity of EMR/ESD at establishing a correct diagnosis.

METHODS

This retrospective study enrolled 96 patients proven as GAC on index forceps biopsy. ESD (17/96, 17.7%), EMR (5/96, 5.2%), OP (20/96, 20.8%), and other treatment or follow-up (54/96, 56.3%) were performed. We analyzed the initial endoscopic and histologic characteristics of GAC lesions, predictive of neoplasm.

RESULTS

After diagnostic modalities, the final pathologic diagnoses were cancer (36/96, 37.6%), dysplasia (9/96, 9.4%), and non-neoplasm (51/96, 53.0%). In univariate analysis, age [odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01-1.07], lesion size of 10 mm or greater (OR 3.94, 95% CI 1.61-9.61), lesion with depressed type (OR 2.50, 95% CI 1.09-5.72), and presence of H. pylori (OR 2.83, 95% CI 1.11-7.25) were risk factors for neoplasm. In multivariate analysis, lesion size of 10 mm or greater (OR 3.63, 95% CI 1.23-10.66), lesion with depressed type (OR 2.86, 95% CI 1.11-7.38) were independent risk factors for cancer.

CONCLUSION

Considering the neoplastic risk of GAC, which could be missed on biopsy, more comprehensive tissue sampling via EMR/ESD might be necessary to establish a definite diagnosis.

Assessment of gastric phenotypes using magnifying narrow-band imaging for differentiation of gastric carcinomas from adenomas

Background. Conventional white-light endoscopy and forceps biopsy are insufficient for definitive diagnosis of gastric adenoma. Immunohistochemical studies have reported an obvious phenotypic difference between adenomas and carcinomas. We investigated the utility of narrow-band imaging with magnifying endoscopy (NBI-ME) for mucin phenotypic assessment to differentiate carcinomas from adenomas. Methods. NBI-ME findings were classified into A, B, and AB types, which revealed papillary, tubular pits and groove microstructures, respectively. To investigate A-B classifications retrospectively, 137 patients (155 lesions) that were diagnosed pretherapeutically with adenoma or borderline lesions by biopsy were enrolled. The mucin phenotype was analyzed immunohistochemically in the first 60 lesions. Results. After endoscopic submucosal dissection, A type and AB type lesions were determined histologically as carcinoma (81/82, 99%). B type lesions were adenoma (29/73, 40%) and carcinoma (44/73, 60%). A or AB type correlated to histological carcinomas (sensitivity 65%, specificity 97%, and accuracy 71%). Mucin phenotypes were gastric or gastrointestinal in A type and AB type carcinomas (31/37, 84%) and intestinal in B type adenomas and carcinomas (21/23, 91%). Conclusions. NBI-ME has the advantage of the assessment of mucin phenotypes in gastric carcinomas and adenomas. The proposed A-B classification is useful, especially for differentiation of gastric or gastrointestinal carcinomas from adenomas.

Endoscopic features suggesting gastric cancer in biopsy-proven gastric adenoma with high-grade neoplasia

AIM

To elucidate the endoscopic features that predict the cancer following endoscopic submucosal dissection (ESD) in patients with high-grade neoplasia (HGN).

METHODS

We retrospectively analyzed the medical records of patients who underwent ESD of gastric neoplasms from January 2007 to September 2010. ESD was performed in 555 cases involving 550 patients. A total of 112 lesions from 110 consecutive patients were initially diagnosed as HGN without cancer by forceps biopsy, and later underwent ESD. We classified lesions into two groups according to histologic discrepancies between the biopsy and ESD diagnosis. Gastric adenoma in the final diagnosis by ESD specimens were defined as adenoma group. Lesions with coexisting cancer after ESD were defined as cancer group.

RESULTS

The mean age was 65.3 years, and 81 patients were male. There was no significant difference in the age or gender distribution between the adenoma (n = 52) and cancer (n = 60) groups. Thirty-six of these lesions (32.1%) showed histologic concordance between the forceps biopsy and ESD specimens, 16 (14.3%) showed a downgraded histology (low-grade neoplasia), and 60 (53.6%) showed an upgraded histology (cancer). A red color change of the mucosal surface on endoscopy was found in 27/52 (51.9%) of cases in the adenoma group and in 46/60 (76.7%) of cases in the cancer group (P = 0.006). Ulceration of the mucosal surface on endoscopy was found in 5 (9.6%) of 52 lesions in the adenoma group and in 17 (28.3%) of 60 lesions in the cancer group (P = 0.013). In the multivariate analysis, a reddish surface color change and mucosal ulceration were significant predictive factors correlated with cancer after ESD of the HGN by forceps biopsy.

CONCLUSION

HGN with a red color change or mucosal ulceration correlated with the presence of gastric cancer. These finding may help to guide the diagnosis and treatment.

Effect of Helicobacter pylori eradication on subsequent dysplasia development after endoscopic resection of gastric dysplasia

BACKGROUND/AIMS

Eradication of Helicobacter pylori reduces the incidence of gastric cancer, and may inhibit gastric dysplasia progression into gastric cancer. The aim of this study was to investigate the effect of eradication of Helicobacter on the incidence of subsequent gastric dysplasia development after endoscopic resection.

METHODS

Medical records of patients who underwent endoscopic resection for gastric dysplasia were retrospectively reviewed. Presence of H. pylori was assessed by the Campylobacter-like organism test and histology. The rate of subsequent dysplasia development after endoscopic resection between the eradication group and non-eradication group was compared.

RESULTS

Total of 129 patients positive for H. pylori infection were included for analysis. Of these, 85 patients received successful eradication therapy and 44 patients did not receive eradication therapy or failed to achieve successful eradication. Sex, mean age and pathologic grade of dysplasia did not differ between the two groups. In univariate analysis, the grade of intestinal metaplasia (p=0.013) significantly differed between metachronous dysplasia group and non-metachrounous dysplasia group. In multivariate analysis, eradication of H. pylori (p=0.014) was related to reduced incidence of subsequent gastric dysplasia development after endoscopic resection.

CONCLUSIONS

Eradication of H. pylori likely has a beneficial effect in preventing the development of subsequent gastric dysplasia, a premalignant lesion of gastric cancer, after endoscopic resection.

Is lesion size an independent indication for endoscopic resection of biopsy-proven low-grade gastric dysplasia?

BACKGROUND/AIM

The standard treatment for patients with gastric low-grade dysplasia (LGD) remains controversial, even though diagnosis of LGD is increasingly common as esophagogastrodeuodenoscopy becomes more available. The aim of this study was to identify a lesion size cut-off as an indication for endoscopic resection (ER) for patients with LGD.

RESULTS

We retrospectively reviewed 285 lesions initially diagnosed as LGD by endoscopic forceps biopsies (EFB) from 2007 to 2010 in Kyung Hee University Hospital, Seoul, Korea. All patients underwent ER. A total of 285 lesions from 257 patients were assessed. After ER, 239 LGD (83.9 %) showed histological concordance and the remaining 46 (16.1 %) cases revealed an upgraded histology [22 high-grade dysplasia (7.7 %), and 24 differentiated adenocarcinoma (8.4 %)]. Univariate analyses demonstrated that lesion size, erythema, depression, and erosion were significant predictors of upgraded LGD (P < 0.001). Multivariate analysis showed that a lesion size ≥2 cm, erythema, and a depressed-type lesion were independent predictors of upgraded histology (P = 0.014, odds ratio 3.27, 95 % confidence interval 1.28-8.39).

CONCLUSIONS

Our data suggest that a substantial number of LGD diagnoses based on EFB were not representative of the entire lesion. We recommend ER if gastric LGD has at least one of the following risk factors: surface erythema and a depressed type regardless of size, or ≥2 cm size regardless of abnormal surface configuration.

Clinicopathologic factors and outcomes of histologic discrepancy between differentiated and undifferentiated types after endoscopic resection of early gastric cancer

BACKGROUND

Histologic discrepancies among specimens obtained by forceps biopsy and endoscopic resection (ER) between the differentiated and undifferentiated types often occur in early gastric cancer (EGC). This study aimed to evaluate the predictive clinicopathologic characteristics and clinical implications of histologic discrepancies in EGC.

METHODS

From August 2005 to March 2012, 596 lesions from 579 patients underwent ER for EGC. The lesions studied were diagnosed as the differentiated histologic type from forceps biopsy specimens. The lesions were grouped according to the occurrence of histologic discrepancy between the differentiated and undifferentiated types in specimens obtained by ER as concordant (n = 570) or discordant (n = 26). The main outcome measures were en bloc resection, complete resection, and curative resection rates.

RESULTS

The histologic discrepancy rate was 4.4% among the studied lesions. Larger size, lesion location in the mid third of the stomach, easy friability, exudates, and submucosal invasion shown on endoscopic ultrasound were significantly related to histologic discrepancy in the univariate analysis. In the multivariate analysis, lesion location in the mid third of the stomach [odds ratio (OR) 5.34, 95% confidence interval (CI) 1.59-19.13] and easy friability (OR 29.26, 95% CI 2.30 to >999.9) were significant factors associated with histologic discrepancy. The complete resection and curative resection rates were significantly lower and the additional operation rates after ER were significantly higher in the discordant group.

CONCLUSIONS

The EGCs with histologic discrepancy between the differentiated and undifferentiated types changed the therapeutic outcomes of ER. Easily friable lesions located in the mid third of the stomach carry a significant risk for histologic discrepancy in undifferentiated histology when ER of EGCs is performed.

Observer variability in gastric neoplasm assessment using the vessel plus surface classification for magnifying endoscopy with narrow band imaging

Background/Aims

Recent studies have demonstrated that magnifying endoscopy with narrow band imaging (ME-NBI) facilitates differentiation of early gastric cancer from gastric adenoma using vessel plus surface (VS) classification. This study estimated the interobserver and intraobserver agreement of endoscopists using the Yao VS classification system for the gastric mucosal surface.

Methods

We retrospectively reviewed patients who underwent endoscopic submucosal dissection or endoscopic mucosal resection, and selected cases in which preoperative ME-NBI was conducted. Before testing endoscopists, a 20-minute training module was given. Static ME-NBI images (n=47 cases) were presented to seven endoscopists (two experts and five trainees) who were asked to assess the images in 20 seconds using the Yao VS classification system. After 2 weeks, the endoscopists were asked to analyze the images again. The κ statistic was calculated for intraobserver and interobserver variability.

Results

The mean κ for intraobserver agreement was 0.69 (experts, 0.74; trainees, 0.64). The mean κ for interobserver agreement was 0.42 (experts, 0.49; trainees, 0.40).

Conclusions

We obtained reliable results as assessed by observer variability, with only brief training on VS classification. The VS classification appears to provide an objective assessment of ME-NBI for trainees who are not familiar with ME-NBI.

What is the next step for gastric atypical epithelium on histological findings of endoscopic forceps biopsy?

BACKGROUND

Gastric atypical epithelium on endoscopic biopsy is borderline lesions between benign and malignant. Definitive management of this lesion remains debatable.

AIMS

We aimed to analyze the final histological diagnosis for atypical epithelium on endoscopic biopsy and to examine the discrepancy rate between the final histological diagnosis and the initial endoscopic assessment.

METHODS

This retrospective study finally enrolled 24 cases proven atypical epithelium on initial histology of an endoscopic biopsy. Of 24 cases, endoscopic submucosal dissection (n = 22), operation (n = 1) and follow-up biopsy without endoscopic submucosal dissection (n = 1) were performed.

RESULTS

Of the 24 cases, early gastric cancer (n = 15, 62%) and adenoma (n = 7, 30%) lesions were finally diagnosed in 22 cases. Age, sex, endoscopic results and number of biopsy did not significantly influence the result of final outcome. Between the initial endoscopic assessment and the final histological diagnosis, 12 cases (50%) showed a concordant diagnosis, but eight (33%) and four cases (17%) showed upgraded and downgraded diagnoses, respectively.

CONCLUSIONS

Of atypical epithelium cases, the rate of malignant and premalignant lesions was 92% and it was difficult to distinguish between malignant and benign lesions using the initial endoscopic findings. Therefore, endoscopic submucosal dissection can be considered in patients with atypical epithelium on endoscopic biopsy.

Pathology of gastric cancer and its precursor lesions

Gastric cancers are a histologically heterogenous group of neoplasms arising from unique epidemiologic and molecular backgrounds. There is accumulating evidence that the intestinal type of gastric adenocarcinoma develops through a multistep process beginning with chronic gastritis triggered primarily by Helicobacter pylori and progressing through atrophy, intestinal metaplasia, and dysplasia (intraepithelial neoplasia) to carcinoma. Loss of E-cadherin expression resulting from CDH1 gene alterations is the primary carcinogenetic event in hereditary diffuse gastric cancer. Proximal gastric adenocarcinomas likely result from either gastroesophageal reflux or H pylori gastritis. This article provides an update of the histologic, immunohistochemical, and molecular pathways of gastric cancer and its precursors.

Precancerous lesions in the stomach: from biology to clinical patient management

Gastric cancer is the final step in a multi-stage cascade triggered by long-standing inflammatory conditions (particularly Helicobacter pylori infection) resulting in atrophic gastritis and intestinal metaplasia: these lesions represent the cancerization field in which (intestinal-type) gastric cancer develops. Intraepithelial neoplasia is consistently recognized as the phenotypic bridge between atrophic/metaplastic lesions and invasive cancer. This paper addresses the epidemiology, pathology, molecular profiling, and clinical management of advanced precancerous gastric lesions.

Undifferentiated early gastric cancer diagnosed as differentiated histology based on forceps biopsy

Histological diagnosis before endoscopic resection (ER) is important to determine whether ER should be performed; indeed, the use of ER for undifferentiated early gastric cancer (UD-EGC) remains controversial. The aim was to investigate the clinicopathological features of UD-EGC in ER specimens, diagnosed as differentiated histology based on biopsy. 289 patients with EGC were treated by ER. Among them, 13.1% were diagnosed as UD-EGC after ER, and 18.4% of them showed differentiated histology based on biopsy before ER. We analyzed UD-EGC with differentiated histology (D-group) compared to undifferentiated histology (UD-group) on biopsy. The D-group showed moderately differentiated adenocarcinoma on biopsy and poorly differentiated adenocarcinoma in ER specimens. The D-group was significantly associated with older age, intestinal metaplasia in the surrounding mucosa, and larger size than the UD-group. Gland portion of tumor, mixed-type Lauren classification, submucosal invasion, lymphovascular invasion, and perineural invasion were more common in the D-group than in the UD-group. The number of biopsies was not different between the groups. When comparing the histopathological mapping findings and endoscopic appearances of the D-group, the zone of transition from differentiated to undifferentiated histology was frequently found on one or two peripheral sides of the lesion. In conclusion, areas of EGC greater than 20mm with moderately differentiated histology on biopsy may contain an undifferentiated component. UD-EGC with differentiated histology on biopsy may show more aggressive behavior than UD-EGC, consistent with the biopsy pathology. Biopsy at several peripheral sides of the lesion may be helpful for diagnosis of UD histology before treatment.

Magnifying endoscopy with narrow-band imaging helps determine the management of gastric adenomas

BACKGROUND

There are no clear clinical criteria for the management of gastric lesions diagnosed as adenomas (Vienna classification category 3) by pre-treatment biopsy. In the present study, we examined the feasibility of magnifying endoscopy with narrow-band imaging (ME-NBI) in discriminating early gastric cancers (Vienna classification category 4 or 5) from adenomas in lesions diagnosed as adenomas by pre-treatment biopsy.

METHODS

This was a single-center cross-sectional retrospective study at a tertiary referral center. One hundred thirty-seven consecutive cases of gastric lesions diagnosed as adenomas in pre-treatment forceps biopsy were examined with conventional non-magnifying endoscopy under white light, non-magnifying chromoendoscopy, and ME-NBI. We investigated the association between the final pathological diagnoses (carcinoma or adenoma) and the following factors: lesion size (mm), color (red or white), macroscopic type (depressed or others), presence of ulceration, and positive ME-NBI finding. The presence of an irregular microvascular pattern or an irregular microsurface pattern with a demarcation line between the lesion and the surrounding area was regarded as a positive ME-NBI finding.

RESULTS

Lesion size was significantly larger in carcinomas than adenomas (P = 0.005). Depressed lesion (P = 0.011), red color (P < 0.001), and positive ME-NBI finding (P < 0.001) were significant predictive factors for carcinoma. Multivariate logistic regression confirmed that red color (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.26-7.34, P = 0.14) and a positive ME-NBI finding (OR 13.68, 95% CI 5.69-32.88, P < 0.001) were independent predictive factors for carcinomas. A positive ME-NBI finding was the strongest predictive factor.

CONCLUSIONS

ME-NBI is useful in planning the management of lesions diagnosed as adenomas by pre-treatment forceps biopsy.

Clinical characterization of gastric lesions initially diagnosed as low-grade adenomas on forceps biopsy

AIM

The aim of this study was to elucidate characteristics of gastric lesions that are initially diagnosed as low-grade adenomas and to establish appropriate treatment.

METHODS

We retrospectively reviewed 231 lesions initially diagnosed as gastric adenomas. All forceps biopsy samples were histologically diagnosed as category 3 low-grade adenomas according to the revised Vienna Classification. All patients underwent endoscopic resection with endoscopic findings and post-resection diagnoses evaluated subsequently.

RESULTS

Sixty-three lesions were initially diagnosed as depressed adenomas, and 168 lesions were diagnosed as protruding adenomas. The depressed lesions were significantly smaller (11.6 ± 5.0 mm) than the protruding lesions (17.0 ± 10.8 mm) (P < 0.001). Diagnoses reclassified to category 4 mucosal high-grade neoplasia (i.e. high-grade adenoma, adenocarcinoma in adenoma and adenocarcinoma) were more frequent among depressed lesions (52.4%) than among protruding lesions (31.0%) (P = 0.004). Multivariate analysis of all 231 lesions showed that lesion size larger than 20 mm (P < 0.001) and depressed appearance (including central depression) (P < 0.001) were significant independent factors suggesting cancer. For the 168 protruding lesions, lesion size larger than 20 mm (P < 0.001) and central depression (P < 0.001) were significant independent factors suggesting cancer. For the 63 depressed lesions, lesion size larger than 15 mm (P = 0.016) and a moth-eaten appearance (P = 0.017) were significant independent factors in the pre-treatment diagnosis of cancer.

CONCLUSIONS

Adenocarcinoma lesions were often found in depressed lesions and protruding lesions with central depression. Endoscopic resection for total biopsy is recommended, even if forceps biopsy indicates low-grade adenoma, as pre-treatment biopsy may be inadequate for an accurate histological diagnosis.

The diagnostic role of endoscopic submucosal dissection for gastric lesions with indefinite pathology

OBJECTIVE

Endoscopic forceps biopsy is a fundamental modality for the histologic diagnosis of gastric neoplasms. However, the pathologic findings are not always concordant with the endoscopic interpretations. Currently, repeat endoscopic biopsy is the only way to manage lesion of indefinite pathology such as Category 2 according to the revised Vienna classification. We aimed to elucidate the role of endoscopic submucosal dissection (ESD) in clarifying the final pathologic diagnosis.

METHOD

Among the 2304 gastric ESD cases, a total of consecutive 30 patients with 31 lesions (1.3%) that had a forceps biopsy with indefinite pathology discrepant from the endoscopic findings underwent endoscopic submucosal dissection (ESD) for confirmative diagnosis and treatment.

RESULTS

The final pathologic diagnoses of the ESD specimens were as follows: low-grade dysplasia in 3 patients (9.7%); high-grade dysplasia in 2 patients (6.5%); adenocarcinoma in 15 patients (48.4%); and a benign lesion in 11 patients (35.5%). Cases with adenocarcinoma included nine well-differentiated lesions, four moderately differentiated lesions, and two lesions with signet ring cell carcinoma. The complete en bloc resection rate for neoplastic lesions was 95.0%, and the incidence rates of ESD-related bleeding and perforation were 5.0% and 5.0%, respectively.

CONCLUSION

ESD can be considered an effective and safe alternative therapeutic and diagnostic tool for gastric lesions in cases where the forceps biopsy pathology is discrepant from the endoscopic findings. The overall final neoplastic diagnosis rate after ESD was 64.5%, and ESD should be performed for lesions with red coloration and friability.

The clinical accuracy of endoscopic ultrasonography and white light imaging in gastric endoscopic submucosal dissection

Purpose

Gastric mucosal neoplastic lesions should have characteristic endoscopic features for successful endoscopic submucosal dissection.

Materials and Methods

Out of the 1,010 endoscopic submucosal dissection, we enrolled 62 patients that had the procedure cancelled. Retrospectively, whether the reasons for cancelling the endoscopic submucosal dissection were consistent with the indications for an endoscopic submucosal dissection were assessed by analyzing the clinical outcomes of the patients that had the surgery.

Results

The cases were divided into two groups; the under-diagnosed group (30 cases; unable to perform an endoscopic submucosal dissection) and the over-diagnosed group (32 cases; unnecessary to perform an endoscopic submucosal dissection), according to the second endoscopic findings, compared with the index conventional white light image. There were six cases in the under-diagnosed group with advanced gastric cancer on the second conventional white light image endoscopy, 17 cases with submucosal invasion on endoscopic ultrasonography findings, 5 cases with a size greater than 3 cm and ulcer, 1 case with diffuse infiltrative endoscopic features, and 1 case with lymph node involvement on computed tomography. A total of 25 patients underwent a gastrectomy to remove a gastric adenocarcinoma. The overall accuracy of the decision to cancel the endoscopic submucosal dissection was 40% (10/25) in the subgroup that had the surgery.

Conclusions

The accuracy of the decision to cancel the endoscopic submucosal dissection, after conventional white light image and endoscopic ultrasonography, was low in this study. Other diagnostic options are needed to arrive at an accurate decision on whether to perform a gastric endoscopic submucosal dissection.

Discrepancies in histologic diagnoses of early gastric cancer between biopsy and endoscopic mucosal resection specimens

BACKGROUND

A preoperative histologic diagnosis of neoplasia is a requirement for endoscopic resection (ER). However, discrepancies may occur between histologic diagnoses based on biopsy specimens versus ER specimens. The aim of this study was to assess the rate of discrepancy between histologic diagnoses from biopsy specimens and ER specimens.

METHODS

A total of 1705 gastric lesions, from 1419 patients with a biopsy diagnosis of neoplasia, were treated by ER from September 2002 to December 2008. We compared the histologic diagnosis from the biopsy sample and the final diagnosis from the ER specimen to assess the discrepancy rate. Clinicopathological characteristics of the lesions that were related to the histologic discrepancies were also studied.

RESULTS

An ER diagnosis of gastric cancer was made in 49% (118/241) of lesions diagnosed as borderline lesions from biopsy specimens; this included adenomas and lesions difficult to diagnose as regenerative or neoplastic. The size, existence of a depressed area, and ulceration findings were significant factors observed in these lesions. An ER diagnosis of differentiated type cancer was obtained for 17% (12/63) of lesions diagnosed as undifferentiated type cancer from the biopsy specimens; for these lesions, the color and a mixed histology were significant factors related to the histologic discrepancies.

CONCLUSION

A biopsy diagnosis of borderline lesions or undifferentiated type cancer is more likely to disagree with the diagnosis from ER specimens. Endoscopic characteristics should be considered together with the biopsy diagnosis to determine the treatment strategy for these lesions.

Endoscopic submucosal dissection of early gastric cancer

Gastric cancer is the most common cancer worldwide. The proportion of early gastric cancer (EGC) cases at diagnosis has increased because of the use of mass screening endoscopy in older adults. Endoscopic mucosal resection has become the standard treatment for EGC in cases with standard indications because of its low risk of lymph node metastasis. A new endoscopic method, endoscopic submucosal dissection, has recently become available. This method allows en bloc resection without limitation of the size of the lesion. The goal of this article is to review the history and methods of endoscopic treatment with EGC, the conventional and extended indications, the therapeutic outcomes, and the complication rates.

[Pathology of endoscopic submucosal dissection; how do we interpret?]

It is widely accepted that endoscopic submucosal dissection (ESD) is an important treatment option for cases of early gastric carcinoma where the probability of lymph node metastasis is very low. The resected ESD specimens are carefully examined by serial sections at 2 mm intervals, and if pathology reveals submucosal invasion more than 500 μm and/or lymphovascular invasion, or if the resection margin is involved by the tumor, surgery is recommended. In this point of view, thorough pathologic examination and reporting the accurate pathologic diagnosis of ESD specimen is very important. The diagnostic approach and pitfalls in the diagnosis of ESD specimen are reviewed.