Possible neoplastic transformation within gastric hyperplastic polyp. Application of endoscopic polypectomy

Endoscopic findings and outcomes of gastric mucosal changes relating to potassium-competitive acid blocker and proton pump inhibitor therapy

Gastric mucosal changes associated with long-term potassium-competitive acid blocker and proton pump inhibitor (PPI) therapy may raise concern. In contrast to that for PPIs, the evidence concerning the safety of long-term potassium-competitive acid blocker use is scant. Vonoprazan (VPZ) is a representative potassium-competitive acid blocker released in Japan in 2015. In order to shed some comparative light regarding the outcomes of gastric mucosal lesions associated with a long-term acid blockade, we have reviewed six representative gastric mucosal lesions: fundic gland polyps, gastric hyperplastic polyps, multiple white and flat elevated lesions, cobblestone-like gastric mucosal changes, gastric black spots, and stardust gastric mucosal changes. For these mucosal lesions, we have evaluated the association with the type of acid blockade, patient gender, Helicobacter pylori infection status, the degree of gastric atrophy, and serum gastrin levels. There is no concrete evidence to support a significant relationship between VPZ/PPI use and the development of neuroendocrine tumors. Current data also shows that the risk of gastric mucosal changes is similar for long-term VPZ and PPI use. Serum hypergastrinemia is not correlated with the development of some gastric mucosal lesions. Therefore, serum gastrin level is unhelpful for risk estimation and for decision-making relating to the cessation of these drugs in routine clinical practice. Given the confounding potential neoplastic risk relating to H. pylori infection, this should be eradicated before VPZ/PPI therapy is commenced. The evidence to date does not support the cessation of clinically appropriate VPZ/PPI therapy solely because of the presence of these associated gastric mucosal lesions.

Incidence and natural history of gastric high-grade dysplasia in patients with familial adenomatous polyposis syndrome

BACKGROUND AND AIMS

Familial adenomatous polyposis (FAP) is characterized by high risks of colonic and extracolonic tumors. Recent studies have suggested a rising risk for gastric cancer (GC). We sought to define the spectrum of premalignant gastric polyps in FAP, focusing on high-grade dysplasia (HGD).

METHODS

The gastric phenotypes of 118 patients diagnosed with FAP or attenuated FAP in our Hereditary Gastrointestinal Cancer Registry were retrospectively reviewed. To analyze the clinical features associated with the diagnosis of HGD, we established an age- and sex-matched control group of FAP patients from our cohort without gastric HGD in a 4:1 ratio.

RESULTS

The spectrum and frequency of gastric polyps in individuals with FAP included fundic gland polyps (67.9%), hyperplastic polyps/foveolar hyperplasia (19.6%), tubular adenomas (15.2%), foveolar adenomas (10.7%), and pyloric gland adenomas (6.3%). Ten patients (8.9%) exhibited gastric HGD at a mean age of 55 ± 13 years, and HGD was seen in all polyp types. When compared with control subjects, HGD was associated with a high diversity of gastric polyp histology, prior low-grade dysplasia, severe gastric polyposis, and prior Whipple surgery (P = 2.0E-5, .003, .024, and .04, respectively). Two patients (1.7%) with HGD were diagnosed with GC. However, the remaining 8 patients with HGD have been under surveillance for an average of 5.8 ± 4.5 years without progression to GC.

CONCLUSIONS

Gastric HGD in FAP may be more common than previously appreciated. The natural history of HGD is variable, and most patients with HGD do not appear to progress to GC.

Academy of Medicine, Singapore clinical guideline on endoscopic surveillance and management of gastric premalignant lesions

Gastric cancer (GC) has a good prognosis, if detected at an early stage. The intestinal subtype of GC follows a stepwise progression to carcinoma, which is treatable with early detection and intervention using high-quality endoscopy. Premalignant lesions and gastric epithelial polyps are commonly encountered in clinical practice. Surveillance of patients with premalignant gastric lesions may aid in early diagnosis of GC, and thus improve chances of survival. An expert professional workgroup was formed to summarise the current evidence and provide recommendations on the management of patients with gastric premalignant lesions in Singapore. Twenty-five recommendations were made to address screening and surveillance, strategies for detection and management of gastric premalignant lesions, management of gastric epithelial polyps, and pathological reporting of gastric premalignant lesions.

Low Risk of Neoplasia and Intraprocedural Adverse Events in Gastric Hyperplastic Polypectomy

GOALS

Assess neoplasia and polypectomy-related adverse event (AE) rates in gastric hyperplastic polyps (GHPs).

BACKGROUND

GHPs carry a risk of neoplastic transformation. The rate of neoplastic transformation and the risk of polypectomy-related bleeding are unclear in the West, as data are derived from Asian or small studies. The authors aimed to determine the rate of dysplasia and intraprocedural AEs in GHP polypectomies in a western cohort.

STUDY

A retrospective study of 591 GHPs >1 cm resected in 491 patients in a single referral center on the occurrence of neoplasia and intraprocedural AEs.

RESULTS

The mean age was 74.9±11.1 years, 57% female individuals. The mean polyp size was 2±0.8 cm. There were 11 neoplastic polyps (1.9%) with low-grade dysplasia, high-grade dysplasia, and cancer in 7 (1.3%), 2 (0.3%), and 2 (0.3%), respectively. Neoplasia was associated with age [9 (3.2%) for more than 75 years vs. 2 (0.7%) for less than 75 years; P=0.035], but not with polyp size or gender. Fifty patients (8.5%) had intraprocedural bleeding (IPB) requiring endoscopic intervention, with 3 hospitalizations. There were no perforations or procedure-related deaths. IPB was associated with polyp size and neoplasia. The adjusted odds ratio (95% confidence interval) for IPB was 1.63 (1.2-2.2) for a 1 cm increase in polyp size, and 7.4 (1.9-29.6) for the presence of neoplasia.

CONCLUSIONS

The neoplasia rate in GHPs was 1.9%, lower than most previous reports, with no major intraprocedural AEs. Physicians may consider biopsy and follow-up in frail elderly patients, but the safety of this strategy needs further confirmation.

Risk factors and clinical correlates of neoplastic transformation in gastric hyperplastic polyps in Chinese patients

Gastric hyperplastic polyps (GHPs) have a potential risk of neoplastic transformation, but the responsible mechanisms have not yet been established. We conducted a study involving 55 patients (33 female) who had undergone endoscopic or surgical resection of GHPs. We compared 16 patients who had GHPs showing neoplastic transformation with 39 patients who had non-neoplastic GHPs. We analyzed differences in serology, gastroscopic manifestations and pathology between the two groups in order to establish risk factors that may be associated with neoplastic transformation. The mean age of the cohort was 61.73 ± 9.024 years. The prevalence of positive serum gastric parietal cell antibody (PCA) was 61.8%. 30 of the GHPs with neoplastic formation had a “strawberry-like” appearance with erosions of polyps (P = 0.000). A history of anaemia was a risk factor for GHPs which demonstrated neoplastic transformation (odds ratio [OR], 3.729; 95% confidence interval [CI], 1.099–12.649; P = 0.035). Although the differences were not significant, our data showed higher prevalences of positive serum PCA (P = 0.057), hypergastrinemia (P = 0.062) and female gender (P = 0.146) in the GHP patients who had neoplastic transformation. Multiple polyps in the corpus (P = 0.024) occurred more frequently in serum PCA positive patients. Hypergastrinemia occurred more frequently in Helicobacter pylori negative patients and of these 20/22 patients had a positive PCA (P = 0.007). GHPs are associated with autoimmune metaplastic atrophic gastritis (AMAG). AMAG is probably one of the risk factors for GHPs to undergo neoplastic transformation.

British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma

Gastric adenocarcinoma carries a poor prognosis, in part due to the late stage of diagnosis. Risk factors include Helicobacter pylori infection, family history of gastric cancer-in particular, hereditary diffuse gastric cancer and pernicious anaemia. The stages in the progression to cancer include chronic gastritis, gastric atrophy (GA), gastric intestinal metaplasia (GIM) and dysplasia. The key to early detection of cancer and improved survival is to non-invasively identify those at risk before endoscopy. However, although biomarkers may help in the detection of patients with chronic atrophic gastritis, there is insufficient evidence to support their use for population screening. High-quality endoscopy with full mucosal visualisation is an important part of improving early detection. Image-enhanced endoscopy combined with biopsy sampling for histopathology is the best approach to detect and accurately risk-stratify GA and GIM. Biopsies following the Sydney protocol from the antrum, incisura, lesser and greater curvature allow both diagnostic confirmation and risk stratification for progression to cancer. Ideally biopsies should be directed to areas of GA or GIM visualised by high-quality endoscopy. There is insufficient evidence to support screening in a low-risk population (undergoing routine diagnostic oesophagogastroduodenoscopy) such as the UK, but endoscopic surveillance every 3 years should be offered to patients with extensive GA or GIM. Endoscopic mucosal resection or endoscopic submucosal dissection of visible gastric dysplasia and early cancer has been shown to be efficacious with a high success rate and low rate of recurrence, providing that specific quality criteria are met.

Vimentin-positive gastric adenocarcinoma arising in a hyperplastic polyp

We report a case of vimentin-positive early gastric adenocarcinoma arising in a hyperplastic polyp (HP). A 72-year-old Japanese man was admitted for the detailed examination of a gastric polyp. He had a subtotal gastrectomy due to acute abdomen 12 years ago. Upper endoscopy revealed a pedunculated polyp measuring approximately 2 cm on the greater curvature of upper body of the remnant stomach. Magnifying endoscopy revealed that the microsurface pattern was irregular and partially absent accompanied with irregular microvessels at the upper end of the polyp. We speculated that the lesion was an adenocarcinoma arising in the HP. Endoscopic submucosal dissection (ESD) was performed. Histological examination of the ESD specimen revealed that the lesion consisted of well- to poorly differentiated adenocarcinoma at the protruding lesion and foveolar hyperplastic epithelia at the base of the polyp. Immunohistochemically, most of tumor cells that comprised poorly-differentiated adenocarcinoma were positive for both cytokeratin and vimentin. Although carcinomas have occasionally been found in HPs, the histological features of the present case are considered extremely unusual. To the best of our knowledge, this is the first case of vimentin-positive early gastric carcinoma arising in a HP.

Mutational analysis by next generation sequencing of gastric type dysplasia occurring in hyperplastic polyps of the stomach: Mutations in gastric hyperplastic polyps

Gastric hyperplastic polyps (GHP) are the most common type of polyps occurring in the stomach. Although GHP are broadly interpreted as benign lesions, they may progress to dysplasia and adenocarcinoma.

OBJECTIVE

In this study, we aimed to identify genomic mutations that characterize and may drive malignant transformation in GHP by using next-generation sequencing. Eight GHP (2 with dysplasia, 1 indefinite for dysplasia and 5 without dysplasia) were studied. Only large polyps (>1cm) with gastric differentiation were included in this study, while adenomatous polyps (intestinal-type) were excluded. Immunohistochemistry for MUC2, MUC5A, MUC6, CDX2, p53, and Ki67 was performed. DNA was extracted from formalin-fixed paraffin-embedded sections and sequenced for the detection of somatic mutations. Multiplex sequencing was done with the TrueSeq Amplicon Cancer Panel in the MiSeq platform. Variant annotation and visualization were performed using NextGENe (SoftGenetics) software. No pathogenic mutations were detected in GHP without dysplasia. TP53 gene mutations were the most common alteration in dysplastic GHP (2 of 2 dysplastic cases). PIK3CA mutation was identified in a GHP with pyloric-type dysplasia, whereas foveolar-type dysplasia carried TP53 mutations. In conclusion, TP53 gene mutations are a common alteration in the early dysplastic stage during malignant transformation of GHP. GHP with dysplasia may show dual differentiation. In our study, pyloric-type dysplasia was associated with a PIK3CA alteration whereas foveolar dysplasia carried TP53 mutations. The identification of carcinoma-associated mutations in large GHP provides additional evidence of their neoplastic potential and emphasizes the need for their complete resection and follow-up.

Gastric polyps: Association with Helicobacter pylori status and the pathology of the surrounding mucosa, a cross sectional study

AIM: To assess the endoscopic characteristics of gastric polyps and their association with Helicobacter pylori (H. pylori) status in a predominantly Hispanic population.

METHODS: We conducted a retrospective study of all esophagogastroduodenoscopies performed at our institution. Demographic, endoscopic and histopathological data were reviewed. Categorization of patients into Hispanic and Non-Hispanic was based on self-identification. Patients without resection/biopsy were not included in the analysis. Identification of polyps type was based on histological examination. One way analysis of variance was used to compare continuous variables among different polyp types and Fisher’s exact test was used compare categorical variables among polyp types. Unadjusted and adjusted comparisons of demographic and clinical characteristics were performed according to the H. pylori status and polyp type using logistic regressions.

RESULTS: Of 7090 patients who had upper endoscopy, 335 patients had gastric polyps (4.7%). Resection or biopsy of gastric polyps was performed in 296 patients (88.4%) with a total of 442 polyps removed or biopsied. Of 296 patients, 87 (29%) had hyperplastic polyps, 82 (28%) had fundic gland polyps and 5 (1.7%) had adenomatous polyps. Hyperplastic polyps were significantly associated with positive H. pylori status compared with fundic gland polyps (OR = 4.621; 95%CI: 1.92-11.13, P = 0.001). Hyperplastic polyps were also found to be significantly associated with portal hypertensive gastropathy compared with fundic gland polyps (OR = 6.903; 95%CI: 1.41-33.93, P = 0.0174). Out of 296 patients, 30 (10.1%) had a follow-up endoscopy with a mean duration of 26 ± 16.3 mo. Interval development of cancer was not noted in any of the patients during follow up period.

CONCLUSION: Gastric hyperplastic polyps were significantly associated with positive H. pylori status and portal hypertensive gastropathy as compared with fundic gland polyps.

Prolapsing Gastric Polyp Causing Intermittent Gastric Outlet Obstruction

Gastric polyps are often an incidental finding on upper gastrointestinal endoscopy, with an incidence up to 5%. The majority of gastric polyps are asymptomatic, occurring secondary to inflammation. Prior reviews discussed Helicobacter pylori (H pylori)-associated singular gastric polyposis; however, we present a rare and unusual case of recurrent multiple benign gastric polyposis post H pylori eradication resulting in intermittent gastric outlet obstruction. A 70-year-old independent male, Chinese in ethnicity, with a background of diabetes mellitus, hypertension, and a simple renal cyst presented with a combination of melena, anemia, and intermittent vomiting of partially digested food after meals. Initial gastroscopy was positive for H pylori; thus he was treated with H pylori eradication and proton pump inhibitors. Serial gastroscopy demonstrated multiple sessile gastric antral polyps, the largest measuring 4 cm. Histopathologic examination confirmed a benign hyperplastic lesion. Computed tomography identified a pyloric mass with absent surrounding infiltration or metastasis. A distal gastrectomy was performed, whereby multiple small pyloric polyps were found, the largest prolapsing into the pyloric opening, thus explaining the intermittent nature of gastric outlet obstruction. Such polyps often develop from gastric ulcers and, if left untreated, may undergo neoplasia to form malignant cells. A distal gastrectomy was an effective choice of treatment, taking into account the polyp size, quantity, and potential for malignancy as opposed to an endoscopic approach, which may not guarantee a complete removal of safer margins and depth. Therefore, surgical excision is favorable for multiple large gastric polyps with risk of malignancy.

Neoplasms arising in large gastric hyperplastic polyps: endoscopic and pathologic features

BACKGROUND

Little is known about gastric neoplasms arising from hyperplastic polyps (HPs).

OBJECTIVE

To investigate the risk factors associated with neoplasms within HPs and to evaluate the role of alterations of the p16-cyclin D1-pRb pathway in the malignant transformation of HPs.

DESIGN

Retrospective, case-control study.

SETTING

Tertiary-care center.

PATIENTS

Between May 1995 and January 2011, a total of 809 HPs >1 cm were investigated. Associated neoplasms were present in 30 HPs (case group); 30 HPs without neoplasms were selected as a control group.

INTERVENTIONS

Gastric polypectomy.

MAIN OUTCOME MEASUREMENTS

The risk factors associated with neoplasms within HPs and immunohistochemical expression of p16, cyclin D1, p53, and Ki-67 between case and control groups.

RESULTS

Of the 809 HPs, 15 had associated dysplasia, and 15 had carcinoma. Multivariate analysis showed that neoplasm was associated with patient age (odds ratio [OR] 1.159; 95% confidence interval [CI], 1.243-2.044; P < .001), polyp size (OR 1.103; 95% CI, 1.055-1.152; P < .001), and polyp lobulation (OR 4.549; 95% CI, 1.759-11.0766; P < .001) but not with location, multiplicity, intestinal metaplasia, growth pattern, or Helicobacter pylori infection. Loss of p16 expression and high Ki-67 expression were observed in dysplastic areas of HPs compared with the control group (p16 = 14.3% vs 60%; P = .001, Ki-67 = 60.7% vs 36.7%; P < .001). However, no significant differences were found in nondysplastic areas in both groups.

LIMITATIONS

Single-center, retrospective study.

CONCLUSION

HPs >1 cm may indicate the presence of neoplasms. Loss of p16 and high Ki-67 expression may be markers of HP-associated dysplasia.

Metastatic carcinoma occurring in a gastric hyperplastic polyp mimicking primary gastric cancer: the first reported case

Hyperplastic polyps of the stomach are regarded as benign. However, in rare cases they may contain incipient primary carcinomas. To our knowledge, breast carcinoma metastatic to a gastric hyperplastic polyp has not yet been reported. We describe the case of a 69-year-old woman to whom a gastric polyp was endoscopically excised. The patient had previously undergone a right mastectomy for mixed, invasive ductal and lobular carcinoma 5 years earlier. Histological sections from the gastric lesion showed typical features of hyperplastic polyp with foci of poorly differentiated adenocarcinoma including signet ring cells infiltrating the lamina propria. The histologic findings were consistent with a primary gastric cancer. However, the carcinoma cells were immunopositive for estrogen and progesterone receptors and GATA3 and negative for CDX2, Hep Par 1, and MUC5AC. E-cadherin showed membranous reactivity in some of the carcinoma cells while in others it was negative. Accordingly, metastatic mixed, lobular and ductal breast carcinoma was diagnosed. We conclude that metastatic adenocarcinoma mimicking primary gastric cancer can be rarely encountered in hyperplastic gastric polyps.

Malignant transformation of hyperplastic gastric polyps: An immunohistochemical and pathological study of the changes of neoplastic phenotype

In spite of the evidence that the malignant transformation of gastric hyperplastic polyps (HPs) is a rare event, it must always be taken into account during diagnosis. The aim of the current study was to clarify the mechanism of the malignant transformation of gastric hyperplasia polyps, with focus on phenotypic expression, cell proliferation and p53 overexpression. Immunohistochemistry for mucin phenotypic markers, including MUC1, MUC2, MUC5AC, MUC6, tight junction factors (claudin-3, -4 and -18), an intestinal phenotypic marker [caudal type homeobox 2 (Cdx2)], Ki-67 proliferative index and p53 overexpression, was performed on archival specimens of gastric polyps excised from six patients. Histologically, the intermingled components of several lesions were present in these polyps. Furthermore, the cancer components were predominantly differentiated adenocarcinoma. Immunohistochemically, all hyperplastic components expressed MUC5AC, but did not exhibit positivity for MUC2. Additionally, the majority of hyperplastic components were immunonegative for claudin-3, while claudin-3 positivity was observed in the majority of areas of dysplasia and carcinoma. Expression of claudin-4 was also observed in the majority of cases and claudin-18 was preserved in the hyperplastic, dysplastic and adenocarcinomatous lesions of all cases. Nuclear accumulation of Cdx2 was detected in almost all the samples with dysplasia and carcinoma, while nuclear p53 was detected in 24-80% of the dysplastic areas and >85% of the cancer components. The Ki-67 labeling index appeared to correlate with neoplastic progression. The observations provided evidence that the mechanism underlying malignant transformation of gastric HPs may occur by multistep carcinogenesis, such as the hyperplasia-adenoma (dysplasia)-adenocarcinoma sequence, and these neoplastic cells may acquire various phenotypes during this process.

An overview of current research of gastric hyperplastic polyps

Gastric hyperplastic polyp (GHP) is one of the most common polypoid lesions of the stomach and has the potential of malignant transformation. This article gives a review of recent progress in research of GHP in terms of clinical and pathological factors, pathogenesis, relation with atypical hyperplasia and canceration, molecular biology and mucin expression.

A rare complication of hyperplastic gastric polyp

Hyperplastic gastric polyps are incidentally diagnosed during upper gastrointestinal endoscopy. They are known to cause gastric outlet obstruction and chronic blood loss leading to iron deficiency anemia. However, hyperplastic gastric polyp presenting as acute severe upper gastrointestinal bleeding is very rare. To the best of our knowledge, there have been two cases of hyperplastic gastric polyps presenting as acute gastrointestinal bleeding in the medical literature. We present a case of a 56-year-old African American woman who was admitted to our hospital with symptomatic anemia and sepsis. The patient developed acute upper gastrointestinal bleeding during her hospital stay. She underwent emergent endoscopy, but bleeding could not be controlled. She underwent emergent laparotomy and wedge resection to control the bleeding. Biopsy of surgical specimen was reported as hyperplastic gastric polyp. We recommend that physicians should be aware of this rare serious complication of hyperplastic gastric polyps as endoscopic polypectomy has diagnostic and therapeutic benefits in preventing future complications including bleeding.

Hypervascular gastric masses: CT findings and clinical correlates

OBJECTIVE

This article focuses on masses that are hypervascular on IV contrast-enhanced CT.

CONCLUSION

The rising use of dual-phase IV contrast-enhanced CT will result in an increase in incidental detection of hypervascular gastric masses. Radiologists must be aware of the range of abnormalities that may appear as a hyperenhancing gastric mass because the differential diagnosis includes both benign and malignant lesions.

The clinicopathological features of gastric hyperplastic polyps with neoplastic transformations: a suggestion of indication for endoscopic polypectomy

Background/Aims

Although gastric hyperplastic polyps are usually considered as benign lesions, a low risk of carcinomatous conversion is currently recognized. We aimed to identify the characteristics of hyperplastic polyps undergoing neoplastic transformation.

Methods

A total of 269 gastric hyperplastic polyps from 216 patients removed by endoscopic polypectomy (EP) or surgical resection were enrolled in this study, and their endoscopic pictures and pathology slides were reviewed.

Results

Neoplastic transformation was detected on forceps biopsy specimen in 11 cases. However, the pathology findings from the EP or surgical specimen revealed neoplastic transformation in 14 cases (5.2%; 4 with dysplasia and 10 with adenocarcinoma). No significant difference was found between hyperplastic polyps with and without neoplastic transformation in age, sex, location, number of polyps or gross appearance. However, neoplastic transformations were more frequently found in gastric hyperplastic polyps >1 cm than in polyps ≤1 cm (12 of 143; 8.4% vs. 2 of 126; 1.6%) (p=0.013).

Conclusions

Neoplastic transformations were more frequently found in gastric hyperplastic polyps >1 cm. Therefore, EP should be considered for gastric hyperplastic polyps >1 cm for the accurate diagnosis and definitive treatment.

Gastric preneoplastic lesions and epithelial dysplasia

The incidence of gastric cancer is declining; however, it remains the second most common cause of cancer-related deaths worldwide. This article describes gastric preneoplastic lesions and epithelial dysplasia. The possible role of Helicobacter pylori infection is emphasized.

Histologic characteristics of gastric polyps in Korea: Emphasis on discrepancy between endoscopic forceps biopsy and endoscopic mucosal resection specimen

AIM: To investigate histological characteristics of gastric polyps in the Korean population.

METHODS: We reviewed endoscopic photographs and medical records of patients with gastric polyps who underwent endoscopic mucosal resection from April 1996 through February 2003.

RESULTS: A total of 85 gastric polyps from 74 patients were reviewed. Male-to-female ratio was 1:1.96. Mean age was 59.9 ± 10.8 years. Multiple polyps were observed in 10.8%. Gastric polyps occurred most frequently in the antrum (58.8%). Pathological results on resected specimens were as follows: tubular adenoma 45.9%, hyperplastic polyp 31.8%, inflammatory polyp 9.4%, hamartoma 3.5%, fundic gland polyp 2.4%, tubulovillous adenoma 2.4%, adenocarcinoma 2.4%, dysplasia 1.1%, and mucosal pseudolipomatosis 1.1%. Discrepancy rate between endoscopic biopsy and pathology of resected specimens was 27.1%. There was no relationship between the size of the polyp and concordance rate.

CONCLUSION: There is considerable discrepancy in histologic findings between endoscopic forceps biopsy and resected specimens. Approaches to review of the histology of an entire polyp should be performed, especially when an adenoma is suspected.

Gastric polypoid lesions: analysis of 150 endoscopic polypectomy specimens from 91 patients

AIM

To analyze gastric polypoid lesions in our patient-population with respect to histopathologic features and demographic, clinical, and endoscopic characteristics of patients.

METHODS

Clinical records and histopathologic reports of patients with gastric polypoid lesions were analyzed retrospectively. All lesions had been totally removed by either endoscopic polypectomy or hot biopsy forceps. The histopathologic slides were re-evaluated by the same histopathologist.

RESULTS

One-hundred and fifty gastric polypoid lesions were identified in 91 patients. There were 53 (58%) women and 38 (42%) men with a median age of 53 (range, 31 to 82) years. The most frequent presenting symptom was dyspepsia that was observed in 35 (38.5%) patients. Symptoms were mostly related to various associated gastric abnormalities such as chronic gastritis or H pylori infection rather than polypoid lesion itself. Polypoid lesions were commonly located in the antrum followed by cardia. Out of 150 lesions, 80 (53%) had the largest dimensions less than or equal to 5 mm and only 7 were pedunculated. The frequencies of hyperplastic polyps, foveolar hyperplasia, and fundic gland polyps were 46%, 18%, and 14% respectively. We also detected gastritis varioliformis in 12 specimens, lymphoid follicles in 9, 4 adenomatous polyps in 4, polypoid lesions with edematous mucosa in 4, inflammatory polyps in 3, and carcinoid tumor in 1. Adenomatous changes were observed within two hyperplastic polyps and low grade dysplasia in one adenoma. Histopathologic evaluation of the surrounding gastric mucosa demonstrated chronic gastritis in 72 (79%) patients and H pylori infection in 45 (49%).

CONCLUSION

Hyperplastic polyps are the most frequently encountered subtype of gastric polypoid lesions. They are usually associated with chronic gastritis or H pylori gastritis. Contrary to the previous belief, they may harbour adenomatous changes or dysplastic foci. Therefore, endoscopic polypectomy seems as a safe and fast procedure for both diagnosis and treatment of gastric polypoid lesions at the same session. In addition, edematous mucosa may appear misleadingly as a polypoid lesion in some instances and it can be ruled out only by histopathologic examination.

Benign gastric polyps: morphological and functional origin

The most common types of benign gastric polyps are fundic gland polyps, hyperplastic polyps, and adenomas. The aim of this study was to determine on which morphological and functional background benign gastric polyps develop. The study includes 85 consecutive patients with gastric polyps and sex- and age-matched controls without polyps selected at random from a general population sample. The type of polyp was hyperplastic in 52 (61%), fundic gland in 18 (21%), adenoma in 10 (12%), carcinoid in 2 (2%), hamartoma in 2 (2%), and inflammatory fibroid in 1 (1%) of the cases. Routine biopsies from the gastric corpus and antrum were examined for presence of gastritis and H. pylori. Blood samples were analyzed for H. pylori antibodies, H+,K+-ATPase antibodies, gastrin, and pepsinogen I. Patients with hyperplastic polyps had increased P-gastrin concentrations and S-H+,K+-ATPase antibody titers and decreased S-pepsinogen I concentrations with a high prevalence of atrophic corpus gastritis or pangastritis. A similar pattern was observed among patients with adenomas, whereas patients with fundic gland polyps had normal serology and a lower prevalence of gastritis and H. pylori infection than controls. In conclusion, hyperplastic polyps and adenomas are generally associated with atrophic gastritis. Patients with fundic gland polyps seem to have a sounder mucosa than controls. Whereas the risk of malignant gastric neoplasia is increased in patients with hyperplastic polyps or adenomas, this does not seem to be the case in patients with fundic gland polyps.

Antral hyperplastic polyp causing intermittent gastric outlet obstruction: case report

BACKGROUND

Hyperplastic polyps are the most common polypoid lesions of the stomach. Rarely, they cause gastric outlet obstruction by prolapsing through the pyloric channel, when they arise in the prepyloric antrum.

CASE PRESENTATION

A 62-year-old woman presented with intermittent nausea and vomiting of 4 months duration. Upper gastrointestinal endoscopy revealed a 30 mm prepyloric sessile polyp causing intermittent gastric outlet obstruction. Following submucosal injection of diluted adrenaline solution, the polyp was removed with a snare. Multiple biopsies were taken from the greater curvature of the antrum and the corpus. Rapid urease test for Helicobacter pylori yielded a negative result. Histopathologic examination showed a hyperplastic polyp without any evidence of malignancy. Biopsies of the antrum and the corpus revealed gastritis with neither atrophic changes nor Helicobacter pylori infection. Follow-up endoscopy after a 12-week course of proton pomp inhibitor therapy showed a complete healing without any remnant tissue at the polypectomy site. The patient has been symptom-free during 8 months of follow-up.

CONCLUSIONS

Symptomatic gastric polyps should be removed preferentially when they are detected at the initial diagnostic endoscopy. Polypectomy not only provides tissue to determine the exact histopathologic type of the polyp, but also achieves radical treatment.

Malignant transformation of gastric hyperplastic polyps: alteration of phenotypes, proliferative activity, and p53 expression

The aim of this study was to clarify the mechanism of malignant transformation of gastric hyperplastic polyps, focusing on phenotypic expression, cell proliferation, and p53 overexpression. Twenty-two lesions of gastric hyperplastic polyps with neoplastic foci were selected for this study. The phenotypes were divided into 3 types (G, gastric; incomp I, incomplete intestinal; and comp I, complete intestinal), according to immunohistochemical stains (human gastric mucin [HGM], MUC2, and CD10). The cell proliferative activity by Ki-67 and overexpression of p53 protein were also examined. Eleven of these lesions contained carcinoma components (CA, category 5 by the Vienna classification), 6 of which were accompanied by low-grade dysplasia (LGD, category 3) and 4 of which were accompanied by high-grade dysplasia (HGD, category 4). Another 2 were composed only of HGD, and the remaining 9 were composed of both LGD and HGD components. As a result, 15 LGD, 15 HGD, and 11 CA components were recognized. The 15 LGD components were classified as 1 G type and 14 incomp I type. All hyperplastic components expressed HGM, 5 (22.7%) of which were accompanied by focal intestinal metaplasia demonstrated by MUC2 expression, whereas intestinalization frequently occurred in neoplastic components (93% of LGD, 53% of HGD, and 64% of CA components). The labeling index was 22.2% in hyperplastic, 42.2% in LGD, 55.7% in HGD, and 53.9% in CA components. p53 protein overexpression was recognized in none of hyperplastic, in 40% of the LGD, in 60% of the HGD, and in 45% of the CA components. These results suggest the importance of the dysplasia-carcinoma sequence in malignant transformation of hyperplastic polyps. Interestingly, intestinalization frequently occurs during neoplastic transformation, although it is not common in the surrounding hyperplastic components.

Hyperplastic gastric polyp causing progressive gastric outlet obstruction

Hyperplastic polyps represent 75 to 90% of gastric polypoid lesions. The manifestations of these unique gastric neoplasms vary, including abdominal pain, nausea, and vomiting or gastrointestinal bleeding. The vast majority of these lesions are small, asymptomatic, and found incidentally on radiologic evaluation or endoscopic examination of the upper gastrointestinal tract. Herein we describe a large, benign, pedunculated hyperplastic polyp that led to progressive gastric outlet obstruction. In addition, we provide an overview of gastric polyps and a review of the literature. Excision of gastric polyps by endoscopic or surgical means is recommended as prudent treatment to eliminate occurrence of malignant foci.