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Gastric precancerous diseases (GPD) may deteriorate into early gastric cancer if misdiagnosed, so it is important to help doctors recognize GPD accurately and quickly. In this paper, we realize the classification of 3-class GPD, namely, polyp, erosion, and ulcer using convolutional neural networks (CNN) with a concise model called the Gastric Precancerous Disease Network (GPDNet). GPDNet introduces fire modules from SqueezeNet to reduce the model size and parameters about 10 times while improving speed for quick classification. To maintain classification accuracy with fewer parameters, we propose an innovative method called iterative reinforced learning (IRL). After training GPDNet from scratch, we apply IRL to fine-tune the parameters whose values are close to 0, and then we take the modified model as a pretrained model for the next training. The result shows that IRL can improve the accuracy about 9% after 6 iterations. The final classification accuracy of our GPDNet was 88.90%, which is promising for clinical GPD recognition.

Gastric dysplasia is a neoplastic lesion and a precursor of gastric cancer. The Padova, Vienna, and World Health Organization classifications were developed to overcome the discrepancies between Western and Japanese pathologic diagnoses and to provide a universally accepted classification of gastric epithelial neoplasia. At present, the natural history of gastric dysplasia is unclear. Much evidence suggests that patients with high-grade dysplasia are at high risk of progression to carcinoma or synchronous carcinoma. Therefore, endoscopic resection is required. Although patients with low-grade dysplasia have been reported to be at low risk of progression to carcinoma, due to the marked histologic discrepancies between forceps biopsy and endoscopic specimens, endoscopic resection for this lesion is recommended, particularly in the presence of other risk factors (large size; depressed gross type; surface erythema, unevenness, ulcer, or erosion; and tubulovillous or villous histology). Helicobacter pylori eradication in patients with dysplasia after endoscopic resection appear to reduce the incidence of metachronous lesions.

The surveillance of patients with Barrett mucosa in the distal oesophagus leads to an increase of patients diagnosed with early cancer of the oesophagogastric junction and stomach with only superficial infiltration. Comparable to Asian countries where screening of patients at risk is recommended due to the high incidence of gastric cancer, endoscopic resection of early cancer in the stomach and distal oesophagus is increasing. In spite of the special endoscopic techniques--there are several requirements for the resected specimen which ensure its exact pathohistological evaluation. This is necessary to detect the exact depth of infiltration and the resection margins. To provide an exact pathohistological diagnosis is important for further therapeutic implications and prognosis. Advanced carcinomas of the oesophagus and stomach need multimodal treatment with radiation and chemotherapy. This has a special impact on the tumour which leads to pathohistological detectable changes as estimated in the so-called regression grading., (Georg Thieme Verlag KG Stuttgart · New York.)

Background and Study Aim: The reliability and external validity of narrow band imaging (NBI) in the stomach have not been described consistently. The aim of the current study was to describe and estimate the accuracy and reliability of a simplified classification system for NBI in the diagnosis of gastric lesions., Methods: Consecutive patients undergoing NBI endoscopy at two reference centers (n=85, 33% with dysplasia) were included in two studies. In total, 224 different areas were biopsied and recorded onto video. In the derivation study, previously described NBI features were analyzed in order to develop a simplified classification. In the validation study the accuracy and reliability of this classification were estimated among three groups of endoscopists with different levels of expertise in NBI., Results: The reliability/accuracy results from the derivation study allowed the creation of a simplified NBI classification. In the validation study, "regular vessels with circular mucosa" (pattern A) was associated with normal histology (accuracy 83%; 95% confidence interval [CI] 75 %-90%); "tubulo-villous mucosa" (pattern B) was associated with intestinal metaplasia (accuracy 84%; 95CI 77%-91%; positive likelihood ratio [LR+]=4.75); and "irregular vessels and mucosa" (pattern C) was associated with dysplasia (accuracy 95%; 95CI 90%-99%; LR+=44.33). The reproducibility of these patterns was high (k=0.62). "Light-blue crest" was moderately reliable (k=0.49) but specific (87%) for intestinal metaplasia. A variable vascular density (additional pattern+) was the best feature for Helicobacter pylori gastritis (accuracy 70%; 95CI 59%-80%) but showed only fair reliability (k=0.38). Non-experienced endoscopists presented lower agreement (k=0.6 vs. k=0.75) and accuracy (74% vs. 86%) than international experts/experienced endoscopists., Conclusion: A simplified NBI classification is accurate and reliable for the diagnosis of intestinal metaplasia and dysplasia. The classification should be further assessed and validated on a per-patient assessment of NBI, and by comparing NBI with other imaging technologies., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Aims: Therapeutic guidelines have not yet been established for low-grade gastric adenomas/dysplasias (LGD), which have a low risk of progression to high-grade adenomas/dysplasias (HGD) or to invasive carcinomas. This study aimed to evaluate risk factors for HGD/carcinoma that indicate a need for resection in biopsy-proven LGD lesions., Patients and Methods: In total, 236 LGD lesions from 208 consecutive patients treated with endoscopic resection (ER) were retrospectively studied between 2004 and 2008. The Vienna classification was used for histological diagnosis. A generalized estimating equation (GEE) logistic regression model was used for multivariate analysis., Results: Among the 236 LGD lesions, the final pathology diagnosed 9 (3.8 %) as invasive carcinoma (category 5), 71 (30.1 %) as HGD (category 4), 148 (62.7 %) as LGD (category 3), and 8 (3.4 %) as negative/indefinite for dysplasia (category 1/2). Lesions ≥ 1 cm were classified as HGD/carcinoma in 39.4 % of patients (65/165). Multivariate analysis indicated that size of ≥ 1 cm (OR 1.93 [95 % CI, 1.06 - 3.52]), depressed morphology (OR 3.81 [95 % CI, 1.22 - 11.9]), and erythema (OR 2.49 [95 % CI, 1.31 - 4.72]) were significantly associated with HGD/carcinoma. The OR increased to 47.6 (95 % CI, 4.27 - 530.65) when the risk factors were all positive. The sensitivity and negative predictive value for ≥ 1 risk factors were 93.8 % and 90.9 %, respectively. As the number of risk factors of a lesion increased, the specificity and positive predictive value also increased., Conclusions: Endoscopic resection can be recommended if a low-grade dysplastic lesion has at least one of the following risk factors: depressed morphology, surface erythema, or a size of 1 cm or greater. For lesions that have none of the three risk factors, follow-up endoscopy is recommended., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: Long-term observational studies assessing the incidence of type I gastric carcinoid (typeIGC) in patients with chronic atrophic gastritis are few., Aim: To evaluate the occurrence of typeIGC at diagnosis and during follow-up and to identify patient features associated with the presence of typeIGC in a cohort of chronic atrophic gastritis patients., Methods: Three hundred and sixty-seven chronic atrophic gastritis patients [245 women, age 54 (18-79) years] underwent regular follow-up by gastroscopy. The incidence of typeIGC was determined in chronic atrophic gastritis patients with at least 2 years of follow-up (n = 214). Baseline clinical and histological features were analysed as factors associated with the presence of typeIGC by univariate analysis., Results: Type I gastric carcinoid was diagnosed in nine (2.4%) patients at the moment when chronic atrophic gastritis was diagnosed. After 1463 person-years, six patients developed typeIGC with an annual incidence rate (person-year) of 0.4%. Patients with typeIGC had significantly higher levels of gastrin, chromogranin A and more frequently the presence of body polyps and ECL-dysplasia compared with chronic atrophic gastritis patients without typeIGC., Conclusions: This cohort study shows that typeIGC is a rare complication in patients with chronic atrophic gastritis, and the presence of body polyps and ECL-dysplasia at gastroscopic/histologic evaluation is strongly associated with the presence of typeIGC., (© 2011 Blackwell Publishing Ltd.)

Background: According to the revised Vienna classification, the surgical removal of gastric epithelial neoplasia category 3 (low-grade dysplasia) lesions is not necessary, whereas the removal of category 4 lesions (high-grade dysplasia and intramucosal cancer) is obligatory. However, approximately 15%-30% of low-grade adenomas/dysplasia progress to high-grade lesions or adenocarcinoma, and it is difficult to determine which lesions will advance to true malignancy. The aim of this study was to evaluate the endoscopic, pathological, and immunophenotypic differences between category 3 and 4 lesions according to the revised Vienna classification., Methods: All tissue samples were excised by endoscopic mucosal resection. Fifty-two category 3 tissue samples and 54 category 4 samples were evaluated by endoscopic findings; by pathology examination of the surrounding mucosa; and by CD10, MUC2, MUC5AC, MUC6, and RUNX3 immunohistochemical staining., Results: Univariate analysis showed that the size of the lesion, color change, ulceration, gastritis score of the surrounding mucosa, and positive expression of MUC6 were associated with category 4 lesions. Multivariate analysis showed that the size of the lesion, ulceration, and positive expression of MUC6 were strongly associated with category 4 lesions., Conclusion: Lesions more than 17 mm in diameter or lesions that are associated with ulceration have the potential for malignant transformation. Positive immunoreactivity for MUC6 appears to be a complementary marker for malignant transformation of gastric epithelial neoplasia.

Background and Aim: Gastric cancer is believed to develop by a multistage process. Intestinal metaplasia (IM) is regarded as a premalignant condition; it is classified into subtypes I, II and III. The aim of this study was to evaluate whether the subtypes of IM were associated with progression to gastric cancer., Methods: The study cohort consisted of 861 subjects, categorized as controls, gastric ulcers, dysplasia and cancer. The IM was scored histologically using the Sydney classification for the antrum and the body of the stomach. The biopsies were stained with high iron diamine and alcian blue (pH 2.5) (HID-AB2.5), and the IM was subtyped as I, II or III., Results: The proportion of IM subtypes I, II and III were 14.5%, 47.2% and 38.3% in the antrum, and 28.1%, 57.8% and 14.1% in the body of the stomach, respectively. These distributions did not show significant differences depending on disease or Helicobacter pylori positivity. In cases that were H. pylori-positive, the prevalence of IM subtype II in the cancer and dysplasia groups was higher than in the control group in the body of the stomach (P < 0.05). The proportion of IM subtype III in the antrum increased in proportion with age (P = 0.036)., Conclusions: IM subtyping was not found to play a major role in the prediction of gastric cancer development in Korea. IM subtype III was associated with aging, and IM subtype II appeared to be related to gastric carcinogenesis in the presence of H. pylori infection.

Atrophic gastritis (resulting mainly from long-standing Helicobacter pylori infection) is a major risk factor for (intestinal-type) gastric cancer development and the extent/topography of the atrophic changes significantly correlates with the degree of cancer risk. The current format for histology reporting in cases of gastritis fails to establish an immediate link between gastritis phenotype and risk of malignancy. The histology report consequently does not give clinical practitioners and gastroenterologists an explicit message of use in orienting an individual patient's clinical management. Building on current knowledge of the biology of gastritis and incorporating experience gained worldwide by applying the Sydney System for more than 15 years, an international group of pathologists (Operative Link for Gastritis Assessment) has proposed a system for reporting gastritis in terms of stage (the OLGA staging system). Gastritis staging arranges the histological phenotypes of gastritis along a scale of progressively increasing gastric cancer risk, from the lowest (stage 0) to the highest (stage IV). This tutorial aims to provide unequivocal information on how to consistently apply the OLGA staging system in routine diagnostic histology practice.

Dysplasia is the earliest phase in cancer development that can be recognized by routine morphology. High grade dysplasia, intraepithelial carcinoma and in situ carcinoma are synonymous terms identifying a non invasive lesion whereas superficial (early) carcinoma is defined as a lesion confined to the mucosa or to the mucosa and sub-mucosa with or without lymph node metastasis. In the Vienna classification, proposed by a panel of Western and Japanese experts in 2000, the term "dysplasia" was replaced by the term "intraepithelial neoplasia" because this term defines more clearly the nature and the extent of the lesion, allowing recommendations for further diagnostic and therapeutic measures. Intraepithelial neoplasia is divided into two groups: low grade and high grade. Superficial oeso-gastric cancer can be treated by endoscopic mucosal resection (EMR). EMR provides specimens that must be handled and reported as surgical specimens by the pathologist.

Premalignant esophagogastric (EG) lesions develop against a background of chronic inflammation, called a premalignant condition. For esophageal squamous cell cancer, causal factors include alcohol, tobacco, hot beverages, oral consumption of opioids, and probably infectious agents. For adenocarcinoma in the Barrett's esophagus (BE), gastroesophageal reflux disease (GERD) is the principal causal factor. At the EG junction, adenocarcinoma arises either from the esophagus or from the proximal stomach (cardia). In the distal stomach, chronic gastritis with atrophy is the premalignant condition related to Helicobacter pylori infection. A high intake of salt and low intake of antioxidants also play a role. The histopathology of EG premalignant lesions is now included in the groups low-grade and high-grade intraepithelial neoplasia (IEN) of the revised Vienna classification. Endoscopy is the gold standard for detection of the lesions at the preclinical stage and their appearance is described in subtypes of the type 0 of the Japanese classification, with a distinction between protruding and nonprotruding lesions. There is a priority for primary prevention of causal factors rather than for mass screening, which is justified only in Japan for the prevention of stomach cancer. The trend to early detection of premalignant lesions justifies the development of mini-invasive endoscopic procedures of treatment.

Intestinal metaplasia is a premalignant condition that occurs in the upper gastrointestinal tract and can be subdivided into three types (I, II and III). Previous studies suggest that type III carries the highest cancer risk. The high iron diamine/alcian blue (HID/AB) technique traditionally has been used to identify this subtype; however, the technique uses reagents that are toxic and potentially carcinogenic. Therefore, in this study we evaluate various alternative histochemical techniques. Our results indicated that the only suitable alternative is Gomori's aldehyde fuchsin/AB technique. The study also revealed that subtyping of intestinal metaplasia is a subjective procedure, open to varying interpretation. Consequently, we suggest that previous work linking cancer risk to metaplasia subtypes should be viewed with some circumspection.

The Sydney system recommends sites and numbers of stomach biopsies (mapping) for evaluation of Helicobacter pylori-associated lesions. The diagnostic yield of the recommended mapping technique in populations at high risk for gastric preneoplastic lesions has not been established. We evaluated pathology data from 733 endoscopies performed as part of an intervention study that assessed the effects of H. pylori treatment on preneoplastic conditions. Two pathologists assessed whether the mapping sequence of the 7 biopsy specimens obtained during each endoscopy was correctly followed and graded the specimens using the Sydney classification for gastritis. If the mapping sequence was followed, then we evaluated whether the amount of information obtained from 3 biopsy samples approximated that obtained from 5 and 7 biopsy samples. The mapping sequence was followed in only 239 (33%) endoscopies, indicating that experienced endoscopists can inadvertently misidentify sites in the stomach when obtaining specimens. When data from 7 specimens were used, H. pylori was found in 205 endoscopies, atrophy in 152, metaplasia in 135, and dysplasia in 22. When data from 3 specimens were used, the sensitivity was 99% for presence of H. pylori, 82% for atrophy and metaplasia, and 81% for dysplasia. When data from 5 specimens were used, the sensitivity was 100% for H. pylori, 96% for atrophy, and 95% for metaplasia and dysplasia. Although site-specific biopsy mapping is difficult in practice, the recommendations of the Sydney system as to the location and number of gastric biopsy specimens can adequately identify significant gastric histopathology., (Copyright 2003, Elsevier Science (USA). All rights reserved.)

Gastric dysplasia is considered to be the penultimate stage of the gastric carcinogenesis sequence. Its clinical importance has been underscored since its association with gastric adenocarcinoma was established. High-grade dysplasia and to a lesser degree low-grade dysplasia are markers of increased cancer risk, although their natural histories are difficult to determine. There are many pitfalls in the diagnosis of gastric dysplasia. Its recognition and grading are subject to interobserver variability, particularly at the lower end of the histologic spectrum (negative v indefinite for dysplasia v low-grade dysplasia) when inflammation is present. Also, diagnostic criteria and grading schemes have evolved differently worldwide resulting in disagreement between pathologists. Against this background, the authors review contemporary issues related to gastric dysplasia, its definition, classification, grading, and natural history. We also discuss new classifications of gastric epithelial dysplasia designed to develop equivalence between grading schemes worldwide.

A worldwide-accepted histologic, classification of the gastric carcinomatous and precancerous lesions is a prerequisite for a consistent recording of epidemiologic data and for both developing and evaluating primary and secondary preventive efforts. Different nomenclatures have been proposed for gastric precancerous lesions in eastern countries and in Japan. This article presents a classification of gastric precancerous lesions resulting from an international consensus conference involving pathologists of different countries. Five main diagnostic categories are identified. To allow comparisons with the nomenclature proposed by the Japanese Research Society for Gastric Cancer, each category was also assigned a numeric identification: 1 = normal, 2 = indefinite for dysplasia, 3 = noninvasive neoplasia, 4 = suspicious for invasive cancer, and 5 = cancer. The interobserver reproducibility of the histologic classification was tested in a series of 46 cases. By collapsing benign alterations (categories 1+2) versus noninvasive neoplasia (category 3) versus suspicious for invasive cancer and fully appearing carcinomatous lesions (categories 4+5), the general agreement value was 77.7%, whereas kappa coefficient was 0.63. By examining gastric precancerous lesions from diverse populations, the authors agreed that the gastric precancerous process is universal and the differences in nomenclatures are merely semantics. The international Padova classification of the gastric precancerous lesions is submitted to the attention of the international scientific community, which is invited to test and to improve on it.

Background: Gastric neoplastic lesions labelled as high-grade adenoma/dysplasia by Western pathologists are often diagnosed as mucosal carcinoma by Japanese pathologists. We examined whether stratifying histological diagnoses by invasion status could increase the extent of agreement between Western and Japanese pathologists and could reduce the frequency of discrepant diagnoses between biopsy samples and corresponding resected specimens., Methods: Thirty-five histological slides of gastric lesions that had previously been individually reviewed by eight expert gastrointestinal pathologists from Japan, North America and Europe were reassessed by the same pathologists with particular attention to the aspect of invasion. Kappa statistics were used to determine the extent of agreement between Western and Japanese pathologists before and after reclassifying the diagnoses according to invasion status. Moreover, we examined the number of discrepant assessments regarding 14 lesions of which there were both biopsy specimens and resected specimens., Results: There was agreement between the Western and Japanese pathologists in only 11 (31%) of the 35 slides (kappa coefficient 0.15) when traditional diagnostic categories were used. However, after high-grade adenoma/dysplasia, noninvasive carcinoma and suspected carcinoma were grouped together, there was better agreement, namely in 22 (63%) of the slides (kappa coefficient 0.41). Moreover, such reclassification significantly reduced the number of discrepant diagnoses between biopsy and endoscopic mucosal resection specimens by three Western pathologists, from 19 (45%) of 42 assessments when high-grade adenoma/dysplasia was grouped together with low-grade adenoma/dysplasia, to 6 (14%) of 42 assessments when grouped with suspected and definite carcinoma., Conclusions: To improve the international comparability of gastric histological diagnoses we recommend that high-grade adenoma/dysplasia, noninvasive carcinoma and suspicion of invasive carcinoma be grouped together as a single category of noninvasive high-grade epithelial neoplasia.

It is widely acknowledged that most stomach carcinomas developed from dysplastic lesions of gastric mucosa. They can be found in known precancerous conditions as chronic gastritis, gastric adenoma, giant rugal hypertrophy, chronic peptic ulcer, gastric stump after partial resection and pernicious anemia. Several grading systems of gastric dysplasia have been suggested. Nagayo's or the ISGGC classification was applied to 367 biopsy specimens of 258 patients between 1979-1995. The frequency of moderate and severe dysplasia was 0,84% regarding all gastric endoscopies in the same period of time. Follow-up studies were performed in 56 cases in a period of 1 7 ys. In this group cancer developed during 14 patients. The authors' recommendation is to follow up the patients gastric dysplasia for least 10 ys after with diagnosis.

Background: Within the framework of a chemoprevention trial on stomach cancer, two substudies based on repeat measurement were undertaken to evaluate reliability of histological diagnoses of gastric precancerous lesions., Methods: A subgroup of 45 subjects received two endoscopies separated by a period of one month. The two biopsies were reviewed by a single pathologist. A second subsample of 50 subjects had a single endoscopy and the biopsy results were reviewed by two pathologists. Agreement between the two diagnoses was assessed by Cohen's Kappa and by repeat frequency., Results: When the same samples were reviewed by the pathologists involved in the trial, agreement was very high for advanced lesions (repeat frequency = 0.96 for intestinal metaplasia and 1.00 for dysplasia) but lower for less advanced lesions (repeat frequency = 0.73 for superficial gastritis and chronic gastritis, 0.65 for atrophic gastritis). When the same pathologist reviewed two sets of biopsies taken less than 2 months apart, the combination of random observer error and biopsy sampling error gave rise to quite low agreement, especially for early lesions, mainly attributable to biopsy sampling error. Comparison of diagnoses made at routine reading and at review by the same pathologist and by different pathologists showed substantial overall agreement with the exception of one pathologist for whom agreement was moderate., Conclusions: These results confirm that misclassification of histological diagnosis may be a relevant problem in chemoprevention trials of stomach cancer, more so when baseline diagnosis is taken into account in the analysis to estimate progression and regression rates of precancerous lesions. Further, the results suggest that misclassification is limited to early lesions, while diagnostic reliability of severe lesions is quite high.

Gastric epithelial dysplasia (GED) hypothetically is a straight-forward concept: dysplastic epithelium replacing the normal gastric epithelium of the stomach. However, since its inception several decades ago, the term GED has become progressively complex and confusing because of differences in definitions and nomenclature that have been based on cytological, microscopic, endoscopic, or gross features. This has resulted in the terms "dysplasia," "adenoma," "flat adenoma," and "depressed adenoma." Some authors have also included reactive changes under the term "dysplasia."

One of the fundamental problems in the pathology of gastric epithelium is differentiation of reactive or regenerative proliferations, which are not precancerous from precancerous proliferations (i.e. dysplasia) and cancer. Diagnostic and interpretational difficulties, a need for a close cooperation between pathologists and clinicians and an attempt to more precisely assess gastric epithelial dysplasia prompted us to evaluate the usefulness of the current morphological criteria in the diagnosis and grading of gastric epithelial proliferations. The present study indicates that there are no sufficient grounds for grading of dysplasia, although the current morphological criteria permit establishment of a correct diagnosis. Therefore, the currently used three-grade classification of dysplasia may be successfully replaced with an easier two-grade classification or resigned totally.

The histological gastritis classification according to the Sydney system is a standardisation of different classification systems used so far. It is based on the principles of etiology, topography and course of the disease, as well as morphological changes of the gastric mucosa in gastritis. Histological examination represents the practical gold standard of Helicobacter pylori detection and can be used on routinely formaldehyde-fixed biopsy material and hematoxylin-eosin stained slides. Histology is therefore also of practical diagnostic value for the control of the eradication therapy of Helicobacter pylori. The sensitivity of histological Helicobacter detection is on average higher than that of other methods including microbiology. Nevertheless, additional bacterial cultures are useful in cases of therapy resistant Helicobacter pylori infections. For routine diagnosis histological Helicobacter pylori detection is often combined with the so-called rapid urease test, which can be used in the endoscopy outpatient department, frequently offering an interim diagnosis of Helicobacter pylori infection. Furthermore, histological examination enables not only exact gastritis classification with Helicobacter pylori detection, but also the diagnosis of precancerous lesions and gastric carcinomas, as well as primary gastric lymphomas. Biopsy material for histological examination can be taken during the routinely necessary gastroscopic examination of patients with gastric symptoms without much additional burden.

Gastric cancer, especially adenocarcinoma, is variable in incidence on the world. In this paper, there is a review of the epidemiology and the etiopathogenic factors of the disease: genetics, hereditary, immunologic and environmental and, also, of the so called precursor diseases: atrophic gastritis and intestinal metaplasia, gastric adenoma, gastrectomized patients, pernicious anemia and Menetrier's disease. There is an explanation about the changes of the gastric epithelium related both with the intestinal and diffuse type of adenocarcinoma; the anatomo-pathological notion of macroscopic advanced-Borrmann and early cancer-Japanese classification and the clinical and diagnostic procedures are included with the fundamentals of therapeutic management.

The relation between the severity and extent of precancerous lesions in a precancerous condition of the stomach was assessed, to find a means of reducing the endoscopic workload required for the detection of such lesions. 87 subjects who had had gastric surgery for peptic ulcer more than 20 years ago underwent gastric endoscopy and biopsy. Severity of dysplasia correlated with its extent. Severity of intestinal metaplasia correlated with its extent and with severity of dysplasia. Type of operation, but not sex or type of ulcer, was the factor most strongly associated with dysplasia. Previous Billroth II operations were more strongly associated with occurrence of dysplasia (85%) than were other operations. In patients with previous Billroth II operations, moderate and severe dysplasia were commoner around the stoma (37%) than in the body (10%). These findings indicate that there is a relation between the severity and extent of precancerous lesions, which suggests that patients with dysplasia have widespread gastric mucosal instability. They also indicate that, if endoscopic screening is limited to Bilroth II subjects and if biopsies are limited to the stoma, endoscopic workload can be reduced by 85%, with only a small reduction (15%) in detection of moderate and severe dysplasia.

From 1978 to 1988 a malignant lymphoma of the stomach was diagnosed endoscopic-bioptically in 47 patients. In 41 patients it was a primary gastric lymphoma, in 6 a generalized lymphoma. In 20 cases an advanced gastric lymphoma was present which was diagnosed endoscopic-bioptically without problems. In 27 cases, however, lymphomas showed polymorphous lesions which did not look tumorous. In such cases the lymphomas were found in an early stage and bioptic verification was difficult. On an average three bioptic series were needed for histological proof. In 16 lymphomas of this group the malignant infiltration was limited to mucosa/submucosa on operative resection specimens ("early gastric lymphomas") The endoscopic appearance of these early lymphomas was: thickening mucosa-folds (2 cases), extended areas of "regenerative mucosa" and granular pattern (6 cases), mainly multiple irregular ulcerations (8 cases). The above mentioned endoscopic findings are strongly suspected for an early gastric lymphoma and should be clarified by, if needed repeated, bioptic series.

To evaluate the clinical and biological significance of gastric dysplasia, we reviewed the histology of all available specimens of gastric mucosa in 85 patients in whom dysplasia had been previously diagnosed. The initial diagnosis of dysplasia was mild (Dy I) in 23 cases, moderate (Dy II) in 41 cases, and severe (Dy III) in 21 cases. The length of follow-up varied from 3 months to 11 years, with an average of 42 months. The follow-up of cases with Dy I and Dy II suggests that both lesions progress slowly and in most instances will remain stable or regress. In 18 cases, a carcinoma was found--17 in the group of Dy III and one in the group of Dy II. Of the 18 carcinomas, nine were at an early stage. Our data suggest that severe dysplasia is a reliable marker of high risk of gastric cancer and represents a strong indication for a gastrectomy.

Cytological classifications of cancer and precancerous lesions of the lung, breast, esophagus and stomach are suggested. They are based on the analysis of the results of research and practical experience gained at the Institute in the treatment of more than 2,000 cases. The cytological classifications are in conformity with those of WHO and provide for identification of malignancy, histological pattern, degree of tumor differentiation as well as the degree of dysplasia in precancerous lesions.

A review of the literature on the spread, location, morphology, and fate of dysplasia of the gastric mucosa epithelium is presented. Dysplastic conditions of the gastric mucosa epithelium is presented. Dysplastic conditions of the gastric mucosa are noted to occur in all pre-cancer changes of the mucous membrane and to indicate a higher risk of adenocarcinoma development. The degree of this risk in relation to the severity of dysplasia has not yet been established, however. Only severe dysplasia has been found to be topographically associated with gastric carcinoma. Different classifications of dysplasias are presented. On the basis of the data from the literature and their own experience the authors recommend to use classification of dysplasia proposed in 1975 by Grundmann.