Gastric pyloric gland adenoma: a multicentre clinicopathological study of 67 cases

Pathology and Clinical Relevance of Gastric Epithelial Dysplasia

Gastric dysplasia is defined as an unequivocally neoplastic epithelium. Dysplastic lesions are characterized by cellular atypia reflective of abnormal differentiation and disorganized glandular architecture. The last few years have been marked by a refinement of the prognosis and risk of progression of gastric dysplasia and the recognition of novel morphologic patterns of dysplasia. Determination of the correct diagnosis and grade of dysplasia are critical steps since it will be predicting the risk of malignant transformation and help tailor appropriate surveillance strategy. This review describes the morphologic characteristics of conventional dysplasia and nonconventional gastric dysplasia that have been more recently characterized.

Gastrogastric intussusception and acute pancreatitis caused by a large pyloric gland adenoma treated with endoscopic submucosal dissection

Video 1Gastrogastric intussusception and acute pancreatitis caused by a large pyloric gland adenoma treated with endoscopic submucosal dissection: A 75-year-old woman with a several-week history of intermittent postprandial nausea and vomiting presented to the emergency room after experiencing syncope, following several hours of persistent abdominal pain, nausea, and vomiting. A contrast-enhanced CT scan of the abdomen and pelvis was arranged. Axial images show gastrogastric intussusception with the intussusceptum, indicated by the dashed lines, telescoping into the intussuscipiens indicated by the arrowheads. There is a lobulated mass indicated by the asterisk, serving as the lead point for the intussusception, and there is also a small volume of fluid indicated by the arrow, which delineates the mass from the duodenum. In the coronal images, we can again see a long-segment intussusception indicated by the dashed line with a lobulated mass indicated by the asterisk serving as the lead point and extending into the proximal duodenum. Then the lobulated mass occupying and expanding the duodenal lumen can be seen, indicated by the asterisk. Upon entry into the stomach through endoscopy, the gastrogastric intussusception can be seen. The lobulated mass serving as the lead point can be seen being pulled distally. With air insufflation, the intussusception spontaneously resolved. With continued insufflation, within a few minutes, the native confirmation of the polyp was established. It was located in the proximal body along the greater curve with a lobulated appearance with a Paris 1sp morphology. In addition, there was panatrophy in the background mucosa, which was consistent with autoimmune atrophic gastritis that was subsequently confirmed on histopathology and positive anti-parietal cell antibiotics. An EUS was performed and did not show any evidence of T2 disease. Doppler showed large central feeding vessel. A plan was made for endoscopic submucosal dissection (ESD). The strategy for the ESD was an initial circumferential incision and trimming with subsequent application of multipoint traction. After a circumferential incision, a rich vascular supply is seen. After completion of the incision and trimming, the snare was advanced over the scope and the clip advanced through the instrument channel. Multiple clips were then used to secure the snare to the distal end of the lesion. With traction applied, access to the submucosa became much easier and the ESD proceeded easily. For the final remnant of submucosa, it was more easily dissected in a forward view. Chess is one of the merits of multipoint traction in that traction can be applied both proximally and distally to the lesion. The lesion was resected en bloc. The specimen was retrieved using the attached snare, but unfortunately, some of the friable head was fragmented because of its large size, yet the base remained intact. Final pathology demonstrated PGD+HGD with clear margins vertically and laterally along the base. This case of gastrogastric intussusception, causing gastric outlet obstruction and acute pancreatitis secondary to a large pyloric gland adenoma, highlights several rare clinical entities. First, gastrogastric intussusception in adults is an exceptionally rare phenomenon, with only a few documented cases reported in the literature. Second, in the case of large gastric neoplasms causing intussusception, rarely the neoplasm may extend down into the duodenum and obstruct the ampulla of Vater causing acute pancreatitis. Furthermore, pyloric gland adenomas are rare gastric neoplasms that tend to be polypoid in morphology and are associated with autoimmune gastritis, predominantly occurring in female patients, as in this case. Lastly, the traditional management for lesions causing gastroduodenal intussusception is surgical because of the risk of malignancy. However, in this case, the patient underwent successful curative and therapeutic endoscopic resection with ESD.

[Pyloric gland adenoma - a rare tumor of the upper gastrointestinal tract with a high risk of malignancy]

BACKGROUND

Pyloric gland adenomas (PGA) are rare neoplasms of the gastrointestinal tract. According to the literature, these lesions may be underdiagnosed, and their true frequency of occurrence is underestimated.

OBJECTIVE

Clinical and morphological analysis of eight PGA cases of the upper gastrointestinal tract.

MATERIAL AND METHODS

The study included 8 cases of detection of PGA. In 7 out of 8 cases, the tumor was diagnosed by examining endoscopic biopsies, in 1 case, PGA was an accidental finding in the surgical material after proximal gastric resection.

RESULTS

6 out of 8 patients were female, the median age was 65 years (minimum 36 years and maximum 78 years). In 6 cases, PDA was localized in the stomach, in 1 - in the esophagus and in 1 - in the duodenum The size of the tumors ranged from 0.6 cm to 7.5 cm. 4 out of 6 stomach tumors appeared on the background of confirmed autoimmune gastritis, 1 - on the background of lymphocytic gastritis. 4 tumors were found in the body of the stomach, 1 - in the cardia, 1 - in the bottom of the stomach. In 2 out of 8 cases, there were signs of malignancy of the tumor with the transition to a highly differentiated adenocarcinoma. According to the results of the IHC study, the absence of a p53 mutation was noted in these cases.

CONCLUSION

PGA should be considered as neoplasms with a high risk of transformation into invasive adenocarcinoma. Increasing the recognition of PGA among pathologists and further understanding of the molecular mechanisms involved in their neoplastic transformation will improve the diagnosis and treatment of this pathology.

Pyloric Gastric Adenoma: Endoscopic Detection, Removal, and Echoendosonographic Characterization

Pyloric gland adenomas (PGAs) are rare neoplasms found not only in the gastrointestinal tract but also in other extragastrointestinal organs. They have potential for malignant conversion, and early detection and removal is imperative to prevent invasive disease. PGAs prove difficult in management and surveillance given their rarity. However, increasing familiarity with histological appearance and use of advanced tools such as echoendosonography can bring greater understanding of their clinical history. We describe a unique case of a PGA detected within a hiatal hernia sac characterized with echoendosonography and highlight the need to develop surveillance protocols for these types of lesions.

Feasibility of underwater endoscopic mucosal resection for endoscopic management of gastric neoplasms in patients with familial adenomatous polyposis

BACKGROUND

Underwater endoscopic mucosal resection (UEMR) has been developed as an effective endoscopic intervention for colon, rectum, and duodenum neoplasms. However, there are no comprehensive reports regarding the stomach, and its safety and efficacy are unknown. We aimed to examine the feasibility of UEMR for gastric neoplasms in patients with familial adenomatous polyposis (FAP).

METHODS

We retrospectively extracted data of patients with FAP who underwent endoscopic resection (ER) for gastric neoplasms at Osaka International Cancer Institute from February 2009 to December 2018. Elevated gastric neoplasms of ≤ 20 mm in diameter were extracted, and conventional endoscopic mucosal resection (CEMR) and UEMR were compared. Furthermore, outcomes after ER until March 2020 were examined.

RESULTS

91 endoscopically resected gastric neoplasms were extracted from 31 patients with 26 pedigrees, and 12 neoplasms underwent CEMR and 25 neoplasms underwent UEMR was compared. The procedure time was shorter for UEMR than for CEMR. There was no significant difference between en bloc resection and R0 resection rates by EMR methods. CEMR and UEMR showed postoperative hemorrhage rates of 8% and 0%, respectively. Residual/local recurrent neoplasms were identified in four lesions (4%), but additional endoscopic intervention (three UEMR and one cauterization) resulted in a local cure.

CONCLUSION

UEMR was feasible in gastric neoplasms of FAP patients, especially in elevated lesions and those of ≤ 20 mm in diameter.

Multifocal Pyloric Gland Adenoma of the Esophagus Treated by Circumferential Endoscopic Submucosal Dissection

Pyloric gland adenoma is a rare neoplasm of the gastrointestinal tract typically observed in the stomach with a substantial malignant potential warranting its resection. While isolated esophageal pyloric gland adenoma has been reported, there is no literature on the encounter of diffuse, multifocal esophageal pyloric gland adenoma or its management. We present a unique case of multifocal pyloric gland adenoma of the esophagus treated by circumferential endoscopic submucosal dissection. We demonstrate endoscopic submucosal dissection to be a feasible management option.

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.

A Standardized Pathology Report for Gastric Cancer: 2nd Edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

A standardized pathology report for gastric cancer: 2nd edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Endoscopic Findings and Treatment of Gastric Neoplasms in Familial Adenomatous Polyposis

PURPOSE

Gastric neoplasia is a common manifestation of familial adenomatous polyposis (FAP). This study aimed to elucidate the clinical characteristics, endoscopic features including fundic gland polyposis (FGPsis), and treatment outcomes of gastric neoplasms (GNs) in patients with FAP.

MATERIALS AND METHODS

A total of 35 patients diagnosed with FAP, including nine patients from four pedigrees who underwent esophagogastroduodenoscopy (EGD), were investigated regarding patient characteristics, GN morphology, and treatment outcomes.

RESULTS

Twenty-one patients (60.0%) had 38 GNs; 33 (86.8%) and 5 (13.2%) were histologically diagnosed with adenocarcinoma and adenoma, respectively. There were no specific patient characteristics related to GNs. Nodule-type GNs were more prevalent in patients with FGP than without (52.2% vs. 0.0%, P=0.002) in the upper body of the stomach. Conversely, depressed-type GNs were fewer in patients with FGPsis than in those without (13.0% vs. 73.3%, P<0.001). Slightly elevated-type GNs were observed in both groups (34.8% vs. 20.0%, P=0.538). Even within pedigrees, the background gastric mucosa and types of GNs varied. In total, 24 GNs were treated with endoscopic submucosal dissection (ESD) and eight with endoscopic mucosal resection (EMR). EMR was selected for GNs with FGPsis because of the technical difficulty of ESD, resulting in a lower en bloc resection rate (62.5% vs. 100%, P=0.014).

CONCLUSIONS

Our study indicates the necessity of routine EGD surveillance in patients diagnosed with FAP. Notably, the morphology and location of GNs differed between patients with and without FGPsis. Endoscopic treatment and outcomes require more attention in cases of FGPsis.

Case Report: Two Is Not (Always) Better Than One: Pyloric Gland Adenoma of the Gastric Cardia and Concurrent Neuroendocrine Cell Dysplasia Arising From Autoimmune Gastritis

Autoimmune gastritis is a chronic immune-mediated disorder characterized by varied clinical manifestations and that should be endoscopically managed over time, as the gastric atrophy contributes to microenvironmental alterations of the stomach milieu, and an increased cancer risk has been linked to this condition. Here, we report the unusual case of a woman who developed a cardiac high-grade pyloric adenoma in a context of previously undiagnosed autoimmune gastritis with synchronous neuroendocrine cell hyperplastic and dysplastic lesions.

Self-Renewal and Cancers of the Gastric Epithelium: An Update and the Role of the Lectin TFF1 as an Antral Tumor Suppressor

In 2020, gastric cancer was the fourth leading cause of cancer deaths globally. About 90% of gastric cancers are sporadic and the vast majority are correlated with Helicobacter pylori infection; whereas familial clustering is observed in about 10% of cases. Gastric cancer is now considered to be a disease originating from dysregulated self-renewal of the gastric glands in the setting of an inflammatory environment. The human stomach contains two types of gastric units, which show bi-directional self-renewal from a complex variety of stem cells. This review focuses on recent progress concerning the characterization of the different stem cell populations and the mainly mesenchymal signals triggering their stepwise differentiation as well as the genesis of pre-cancerous lesions and carcinogenesis. Furthermore, a model is presented (Lectin-triggered Receptor Blocking Hypothesis) explaining the role of the lectin TFF1 as an antral tumor suppressor possibly regulating Lgr5⁺ antral stem cells in a paracrine or maybe autocrine fashion, with neighboring antral gland cells having a role as niche cells.

Management of familial adenomatous polyposis and MUTYH-associated polyposis; new insights

Familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP) are rare inherited polyposis syndromes with a high colorectal cancer (CRC) risk. Therefore, frequent endoscopic surveillance including polypectomy of relevant premalignant lesions from a young age is warranted in patients. In FAP and less often in MAP, prophylactic colectomy is indicated followed by lifelong endoscopic surveillance of the retained rectum after (sub)total colectomy and ileal pouch after proctocolectomy to prevent CRC. No consensus is reached on the right type and timing of colectomy. As patients with FAP and MAP nowadays have an almost normal life-expectancy due to adequate treatment of colorectal polyposis, challenges in the management of FAP and MAP have shifted towards the treatment of duodenal and gastric adenomas as well as desmoid treatment in FAP. Whereas up until recently upper gastrointestinal surveillance was mostly diagnostic and patients were referred for surgery once duodenal or gastric polyposis was advanced, nowadays endoscopic treatment of premalignant lesions is widely performed. Aiming to reduce polyp burden in the colorectum as well as in the upper gastrointestinal tract, several chemopreventive agents are currently being studied.

Pyloric Gland Adenoma of the Esophagus Treated by Endoscopic Submucosal Dissection: A Case Report

A pyloric gland adenoma is a rare neoplasm that occurs most frequently in the stomach and should be removed because of its precancerous potential. Although there have been case reports of pyloric gland adenomas in extragastric areas such as the duodenum, pancreas, and bile duct, esophageal pyloric gland adenoma has never been reported in Korea. Herein, we report a case of esophageal pyloric gland adenoma that was successfully treated by endoscopic submucosal dissection.

Some Morphology Frontiers of Dysplasia in the Tubular Gastrointestinal Tract: The Rodger C. Haggitt Memorial Lecture

This review, based on the content of the 2020 US Gastrointestinal Pathology Society's Rodger Haggitt Lecture, concerns an array of tubular gastrointestinal tract dysplastic or possible "predysplastic lesions" with an almost purely morphologic focus based on our collaborative efforts over the past few years. These processes include esophageal epidermoid metaplasia, Barrett esophagus-associated dysplasia, polypoid gastric dysplastic lesions, small intestinal dysplasia, and the ability of metastases to mimic it, the controversial "serrated epithelial change" encountered in the setting of long-standing ulcerative and Crohn colitis, and recently described anal columnar human papilloma virus-associated neoplasms.

Gastric neoplasms in patients with familial adenomatous polyposis: endoscopic and clinicopathologic features

BACKGROUND AND AIMS

Gastric neoplasms in patients with familial adenomatous polyposis (FAP) occur at a high rate and can cause death. The endoscopic findings of gastric neoplasms in these patients are characteristic but not well recognized. To identify the relevant characteristics to enable early detection, we retrospectively investigated endoscopic findings of gastric neoplasms in patients with FAP and then compared the clinical, histopathologic, and genetic features among subgroups.

METHODS

Of 234 patients with 171 pedigrees at 2 institutes, 56 cases (24%, 133 gastric neoplasms) with 44 pedigrees were examined. Immunostaining was performed for histopathologic evaluation by 1 blinded pathologist. According to the endoscopic findings, gastric neoplasms were divided into 4 types based on location (L: antrum and pylorus, UM: the rest of the stomach) and color (W: white, T: translucent, R: reddish) and their clinicopathologic features examined.

RESULTS

Of the cases, 93% could be classified into a single type. Among histologic phenotypes, high-grade dysplasia was present in 26% (type L), 41% (type UM-W), 0% (type UM-T), and 22% (type UM-R). The immunologic phenotype comprised the gastric type in 69% (93% in Type UM) and the intestinal phenotype, including the mixed type, in 31% (61% in type L). Moreover, 96% of patients had concurrent duodenal neoplasms. Adenomatous polyposis coli gene status was identified in 93% of patients; the pathogenic variant was detected in 98% but did not influence any endoscopic features.

CONCLUSIONS

Gastric neoplasms in patients with FAP were stratified into 4 types according to their endoscopic findings. The endoscopic phenotype was related to the histopathologic phenotype but not to germline variants.

Duodenal neoplasms of gastric phenotype: reports of two cases and a brief review of literature

Duodenal neoplasms of gastric phenotype are uncommon epithelial neoplasms. Pyloric gland adenomas should be recognized as neoplasms with risk for transformation into invasive adenocarcinoma (). Here we report the case histories of two male patients, who presented with duodenal polypoid lesion. Endoscopic polypectomy and endoscopic submucosal dissection were carried out, respectively. Histopathologically, both polyps showed features of neoplasms of gastric phenotype. The clinical and endoscopic features, pathologic features, immunophenotype, molecular pathogenesis, clinical management and prognosis of the two cases will be discussed. We will also briefly review the latest literatures on duodenal neoplasms of gastric phenotype.

Pyloric gland adenoma with low-grade intraepithelial neoplasia: A case report and literature review

RATIONALE

Pyloric gland adenoma (PGA) is often associated with pyloric gland metaplasia. It has high malignant potential but a low clinical diagnosis rate. Therefore, we reported a case of PGA and reviewed the literature to summarize the clinicopathological features of pyloric adenoma.

PATIENT CONCERNS

A 62-year-old female underwent gastroscopy due to intermittent acid regurgitation and heartburn, which revealed a 4×6 mm flat, elevated lesion in the greater curvature of the upper gastric body, with depression in the central region and blood scab attachment.

DIAGNOSIS AND INTERVENTION

Biopsy revealed gastric adenoma with low-grade intraepithelial neoplasia. The patient was treated with ESD, and pathology showed gastric pyloric gland adenoma with low-grade dysplasia. The cells were positive for MUC6 and MUC5AC immunohistochemically.

OUTCOMES

The patient received proton pump inhibitors and gastric mucosal protective agents for one month after ESD. She occasionally presented acid regurgitation and heartburn, with no abdominal pain, abdominal distension, melena, or hematochezia. Follow-up gastroscopy will be reexamined 1 year later.

LESSONS

PGA has nonspecific performance under endoscopy, and its diagnosis mainly depends on pathology. Clinicians need to increase their ability to recognize such lesions and treat them in time to improve the prognosis.

Recent Advances in Digestive Tract Tumors: Updates From the 5th Edition of the World Health Organization "Blue Book"

CONTEXT.—

The World Health Organization Classification of Tumours: Digestive System Tumors, 5th edition, was published in 2019 and shows several impactful changes as compared with the 4th edition published in 2010. Changes include a revised nomenclature of serrated lesions and revamping the classification of neuroendocrine neoplasms. Appendiceal goblet cell adenocarcinoma is heavily revised, and intrahepatic cholangiocarcinoma is split into 2 subtypes. New subtypes of colorectal carcinoma and hepatocellular carcinoma are described. Precursor lesions are emphasized with their own entries, and both dysplastic and invasive lesions are generally recommended to be graded using a 2-tier system. Hematolymphoid tumors, mesenchymal tumors, and genetic tumor syndromes each have their own sections in the 5th edition. New hematolymphoid lesions include monomorphic epitheliotropic intestinal T-cell lymphoma; duodenal-type follicular lymphoma; intestinal T-cell lymphoma, not otherwise specified; and indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. This paper will provide an in-depth look at the changes in the 5th edition as compared with the 4th edition.

OBJECTIVE.—

To provide a comprehensive, in-depth update on the World Health Organization classification of digestive tumors, including changes to nomenclature, updated diagnostic criteria, and newly described entities.

DATA SOURCES.—

The 5th edition of the World Health Organization Classification of Tumours: Digestive System Tumours, as well as the 4th edition.

CONCLUSIONS.—

The World Health Organization has made many key changes in its newest update on tumors of the digestive system. Pathologists should be aware of these changes and incorporate them into their practice as able or necessary.

Helicobacter pylori-negative Gastric Cancer

<i>Helicobacter pylori (H. pylori)</i>-negative gastric cancer is diagnosed when gastric malignancies are found in patients in <i>H. pylori</i>-naïve stomachs. There are four types of noncardiac <i>H. pylori</i>-negative gastric cancers. The signet ring cell-type poorly cohesive carcinoma is most common, followed by the chief cell-predominant type gastric adenocarcinoma of the fundic gland. Extremely well-differentiated adenocarcinoma of the corpus and well-differentiated pyloric gland cancers are rare outside Japan because of country-specific differences in diagnostic criteria. In endemic areas of <i>H. pylori</i> infection, strict criteria are required for diagnosing an <i>H. pylori</i>-naïve stomach. Both invasive and noninvasive <i>H. pylori</i> tests should show negative results in a subject without a history of <i>H. pylori</i> infection. Furthermore, the serum pepsinogen (PG) assay and endoscopic findings of the background gastric mucosa are required to discriminate subjects with past infections owing to spontaneous regression or unintended eradication of <i>H. pylori</i>. There should be no gastric corpus atrophy (PG I ≤70 ng/mL and PG I/II ≤3.0). Gastroscopy should reveal a regular arrangement of collecting venules without gastric xanthoma, metaplastic gastritis, or advanced atrophy over the angle. On biopsy, there should be no gastric atrophy, intestinal metaplasia, neutrophils, or <i>H. pylori</i> infiltration, and only a mild degree of mononuclear cell infiltration is permitted. The types and characteristics of noncardiac <i>H. pylori</i>-negative gastric cancers are summarized in this review, along with current diagnostic challenges found in Korea.

Non-conventional dysplasias of the tubular gut: a review and illustration of their histomorphological spectrum

The increasing use of gastrointestinal endoscopic procedures has led to the recognition by histopathologists of non-conventional (or special-type) dysplasias of the gastrointestinal tract. These lesions can be recognised in association with prevalent underlying gastrointestinal conditions, such as Barrett oesophagus, chronic atrophic gastritis, and inflammatory bowel disease. The diagnosis of these special types can be challenging, and their biological behaviours are not fully characterised. The aim of this review is to provide a global view of non-conventional dysplastic lesions observed in the various segments of the tubular gastrointestinal tract and describe their salient features. Furthermore, as the clinical implications of these various subtypes have not been broadly tested in practice and are not represented in most management guidelines, we offer guidance on the best management practices for these lesions.

The pathology of gastric and duodenal polyps: current concepts

The liberal use of upper endoscopy has led to an increased detection of gastric and duodenal polyps, which are identified in as many as 6 and 4.6% of patient examinations, respectively. Gastroduodenal polyps are a heterogeneous group of lesions that can be neoplastic or non-neoplastic (e.g. hyperplastic or heterotopical). Most polyps present characteristic topographical features, as well as endoscopic appearance and size. Evaluation of the surrounding mucosa is essential in assessing the underlying pathology (e.g. Helicobacter pylori, autoimmune gastritis or inherited polyposis syndromes). Phylogenetically, gastric and duodenal polyps can be classified according to the epithelial compartment from which they derive. Polyps that arise from the surface epithelium can either be of foveolar or intestinal type, and they can develop from either the native mucosa or the metaplastic epithelium (gastric intestinal metaplasia or duodenal foveolar metaplasia). Other polyps develop from the deeper glandular component, such as pyloric/oxyntic gland derived subtypes. In this review we focus upon epithelial polyps, with an emphasis on the most common and clinically relevant lesions, and present recently described entities.

Gastric Epithelial Polyps: When to Ponder, When to Panic

This review provides an overview of different types of gastric epithelial polyps. The polyps are classified based on their cell or epithelial compartment of origin. Some of these polyps can be considered reactive or nonneoplastic, whereas others are neoplastic in origin, are sometimes associated with a hereditary polyposis/cancer syndrome, and may have malignant potential. The aim of this review is to provide a pragmatic overview for the practicing pathologist about how to correctly diagnose and deal with gastric epithelial polyps and when (not) to ponder, and when (not) to panic.

Genetic alteration of colorectal adenoma-carcinoma sequence among gastric adenocarcinoma and dysplastic lesions in a patient with attenuated familial adenomatous polyposis

Background

Familial adenomatous polyposis (FAP) is characterized by colorectal polyposis and adenocarcinoma that is frequently accompanied by extracolonic neoplasm. The risk of gastric carcinoma is increasing in Western FAP patients as well as Asian patients.

Methods

We report the case of an FAP patient with fundic gland polyposis who developed gastric adenocarcinoma and metachronous pyloric gland adenomas. These tumors were endoscopically resected, and immunohistochemistry with gastric mucin (i.e., MUC6, MUC5AC) showed that the tumors belonged to the gastric subtype. Somatic mutation profiles were determined by target amplicon sequencing using a next‐generation sequencer.

Results

Germline APC variant c.5782delC was found by direct sequencing and somatic KRAS mutations in these tumors were identified by next‐generation sequencing. Different KRAS mutation alleles (KRAS p.Gly12Ala, p.Gly12Arg, and p.Gly12Asp) indicated these dysplastic lesions developed from a distinct origin in fundic gland polyposis. Sequential mutations of the APC and KRAS were judged—based on a database search—to be characteristic of the adenoma‐carcinoma sequence in colorectal carcinogenesis.

Conclusion

The colonic adenoma‐carcinoma sequence among gastric adenocarcinoma and dysplastic lesions was indicated in FAP‐associated gastric carcinogenesis.

Gastric pyloric gland adenoma resembling a submucosal tumor: A case report

BACKGROUND

Pyloric gland adenoma (PGA) is a recently described and rare tumor. Submucosal tumor (SMT)-like PGA is more difficult to diagnose and differentiate from other submucosal lesions.

CASE SUMMARY

We present the case of a 69-year-old man with a 10 mm SMT-like elevated lesion with an opening in the upper part of the gastric body, referred to our hospital for further endoscopic treatment. Magnifying endoscopy with narrow-band imaging, endoscopic ultrasonography, and complete endoscopic submucosal dissection were performed on the patient. Histopathological findings revealed tightly packed tubular glands lined with cuboidal or columnar cells that had round-to-oval nuclei containing occasional prominent nucleoli and an eosinophilic cytoplasm similar to that in non-neoplastic gastric pyloric glands. Additionally, immunohistochemical analysis showed positive staining for both mucin 5AC and mucin 6. Therefore, we arrived at the final diagnosis of gastric PGA. Although there was no apparent malignant component in this tumor, PGA has been considered a precancerous disease with a high risk of transformation into adenocarcinoma.

CONCLUSION

PGA should be considered when detecting gastric SMT-like lesions. Physicians and pathologists should focus on PGA due to its malignant potential.

Clinicopathological features of pyloric gland adenomas of the duodenum: a multicentre study of 57 cases

AIMS

To determine the clinicopathological features of pyloric gland adenomas (PGA) that arise in the duodenum.

METHODS AND RESULTS

Fifty-seven cases of duodenal PGA were identified and analysed from 56 patients. Clinicopathological and immunohistochemical analyses were performed. PGA tend to occur in older individuals (median age = 73.5), with a slight female predominance (25 males, 31 females). PGA arise more commonly in the proximal duodenum (68.75% in D1, 25% in D2 and 6.25% in D3) and usually present as mucosal nodules (98.2%) or plaques (1.8%), with a mean size of 14.8 mm. There is associated gastric heterotopia in 22.8% of cases. PGA showing features of high-grade dysplasia were significantly larger in size than PGA, showing only low-grade dysplasia (23.1 versus 8.7 mm; P = 0.0001) and more likely to show a tubulovillous rather than a pure tubular architecture (P = 0.025). In our series, 10 of 56 patients had intramucosal or invasive carcinoma associated with the duodenal PGA (17.9%). Three of these carcinomas showed lymph node metastasis. Following definitive treatment, local recurrence occurred in only three patients.

CONCLUSIONS

Duodenal PGA tend to occur in the proximal duodenum of older individuals. Larger size and tubulovillous architecture correlates with high-grade dysplasia and associated adenocarcinoma. The low recurrence rate of these lesions would suggest that endoscopic management is appropriate, provided that the lesion can be completely resected.

Pyloric Gland Adenoma (PGA) of the Gallbladder: A Unique and Distinct Tumor from PGAs of the Stomach, Duodenum, and Pancreas

Twenty-four surgically resected, gallbladder pyloric gland adenomas (GB-PGAs) were examined and their features were compared with the reported features of stomach, duodenum, and pancreatic PGAs to better understand GB-PGAs. Clinical information on background gallbladder lesions and histologic data, including tumor grade, existence of squamoid morules, intratumoral cholesterosis, and intracytoplasmic mucins were collected. Immunohistochemical staining for MUC2, MUC5AC, MUC6, CDX2, pepsinogen I, p53, and MIB-1/nuclear β-catenin were evaluated. Targeted mutational analyses of KRAS exon2, GNAS exon 7, and CTNNB1 exon 3 were conducted. We found that 29.2% of the GB-PGAs were histologically high-grade dysplasias/carcinomas; 70.8% were low grade; and 20.8% and 33.3% contained squamoid morules and intratumoral cholesterosis, respectively. In addition, 45.8% and 54.2% of GB-PGAs were mucin-rich and mucin-poor types, respectively. Immunohistochemically, MUC6 was diffusely positive in all GB-PGAs; MUC2, MUC5AC, and CDX2 were only focally positive, and no pepsinogen-I positive cells were observed. Nuclear β-catenin accumulation was observed in all cases; however, the ratio varied among cases. Mucin-poor types were significantly associated with high histologic grade dysplasias/carcinomas and high nuclear β-catenin labeling indices. Mutational analyses identified CTNNB1 mutations in 100% of GB-PGAs (21/21), KRAS in 4.2% (1/23), and GNAS in 0% (0/22). The present study clarified the unique histologic features, phenotypic differentiation, and molecular statuses frequently associated with GB-PGAs. Altogether, our data suggest that tumorigenesis of GB-PGA is distinct from that of stomach, duodenum, and pancreatic PGAs.

No transformation of a fundic gland polyp with dysplasia into invasive carcinoma after 14 years of follow-up in a proton pump inhibitor-treated patient: A case report

A fundic gland polyp (FGP) is a common gastric polyp. Intraepithelial neoplasia in FGPs, referred to as FGP with dysplasia, is often seen in patients with familial adenomatous polyposis (FAP). In sporadic FGPs, low-grade dysplasia (LGD) is rare, and high-grade dysplasia (HGD) or carcinoma arising from sporadic FGPs is extremely rare. Because of this rarity, the prognosis and appropriate management of these lesions have not been clarified. In the present case, a sporadic FGP with LGD did not develop into invasive carcinoma, but contained foci of HGD 14 years after diagnosis. The biopsy specimen of the polyp taken at the first esophagogastroduodenoscopy 15 years earlier was diagnosed as FGP without dysplasia. At the second histological examination, LGD was found. Because the polyp increased in size during proton pump inhibitor therapy for 14 years, endoscopic mucosal resection was performed. The pathological diagnosis of the resected specimen was FGP with HGD mixed in LGD, with no invasive carcinoma. Dysplasia in FGPs might have less malignant potential regardless of dysplasia or size.