Pyloric gland adenoma: an entity distinct from gastric foveolar type adenoma. Am J Surg Pathol. 2009;33:186-193. [PMID: 18830123 DOI: 10.1097/pas.0b013e31817d7ff4]

Autoimmune Metaplastic Atrophic Gastritis (AMAG): Regional Demographics and Their Effect on Prevalence

Autoimmune metaplastic atrophic gastritis (AMAG) is a chronic immune-mediated form of gastritis characterized by damage to oxyntic cells, ultimately resulting in both iron deficiency with or without anemia and pernicious anemia. The current dogma is that AMAG is a disease of White Northern European women of advanced age. We, therefore, sought to examine the prevalence of AMAG in biopsies obtained from populations enriched for self-identified Hispanics for cross-comparison against data from previously reported populations enriched for self-identified White, non-Hispanic patients. To that end, we prospectively collected 1708 sequential gastric biopsies performed at the University of Miami Hospitals/Jackson Health Systems clinics from 1692 patients over a 1-year period as well as pertinent clinical parameters. These Florida data were then compared against data previously collected from the Baltimore population, which has far lower numbers of Hispanic patients. Self-identified race and/or ethnicity were used. From these 1692 patients, we identified 79 patients (4.6%) with AMAG. These included 60 women (76%) and 19 men (24%), with a F:M ratio of 3.1:1. Patients had a median age of 60 years (range: 15-83). Self-identified race and/or ethnicity were: 60 (76.0%) Hispanic, 9 (11.4%) Black, 9 (11.4%) White, and 1 Asian (1.2%). The median age at initial presentation was: 51 years (range: 15-83) in Hispanics, 77.2 years (range: 46-74) in Blacks, 59 years (range: 49-79) in Whites, and 58 years in the only Asian patient. The overall demographics of AMAG largely mirrored the Florida population, with an over-representation of Hispanics (Florida inhabitants self-report as 70% Hispanic). The overall 4.6% prevalence of AMAG in the Florida population differed significantly from the 1.1% in Baltimore (p < .00001), a finding that presumably reflects the large Hispanic population. In fact, the prevalence of AMAG is far higher in Hispanic patients. Awareness of these data should increase recognition of AMAG in this population.

ACG Clinical Guideline: Diagnosis and Management of Gastric Premalignant Conditions

Gastric premalignant conditions (GPMC) are common and include atrophic gastritis, gastric intestinal metaplasia, dysplasia, and certain gastric epithelial polyps. GPMC have an increased risk of progression to gastric adenocarcinoma. Gastric cancer (GC) in the United States represents an important cancer disparity because incidence rates are 2- to 13-fold greater in non-White individuals, particularly early-generation immigrants from regions of high GC incidence. The US 5-year survival rate for GC is 36%, which falls short of global standards and is driven by the fact that only a small percentage of GC in the US is diagnosed in the early, curable stage. This document represents the first iteration of American College of Gastroenterology guidelines on this topic and encompasses endoscopic surveillance for high-risk patients with GPMC, the performance of high-quality endoscopy and image-enhanced endoscopy for diagnosis and surveillance, GPMC histology criteria and reporting, endoscopic treatment of dysplasia, the role of Helicobacter pylori eradication, general risk reduction measures, and the management of autoimmune gastritis and gastric epithelial polyps. There is insufficient evidence to make a recommendation on upper endoscopic screening for GC/GPMC detection in US populations deemed high-risk for GC. Surveillance endoscopy is recommended for individuals at high risk for GPMC progression, as defined by endoscopic, histologic, and demographic factors, typically every 3 years, but an individualized interval may be warranted. H. pylori testing, treatment, and eradication confirmation are recommended in all individuals with GPMC. Extensive high-quality data from US populations regarding GPMC management are lacking, but continue to accrue, and the quality of evidence for the recommendations presented herein should be interpreted with this dynamic context in mind. The GPMC research and education agendas are broad and include high-quality prospective studies evaluating opportunistic endoscopic screening for GC/GPMC, refined delineation of what constitutes "high-risk" populations, development of novel biomarkers, alignment of best practices, implementation of training programs for improved GPMC/GC detection, and evaluation of the impact of these interventions on GC incidence and mortality in the US.

MUC5AC immunoreactivity in scattered tumor cells is useful for diagnosing CIC-rearranged sarcoma

CIC-rearranged sarcoma is an aggressive round cell sarcoma, and an alternative ATXN1/ATXN1L fusion has been reported. Diagnosis may be difficult, and molecular assays may suffer from imperfect sensitivity. Characteristic histology and ETV4 immunohistochemical positivity are diagnostically helpful. However, ETV4 staining is unavailable in most laboratories. Here, we explored the diagnostic utility of MUC5AC immunohistochemistry in CIC-rearranged sarcomas. All 30 cases, except one, of CIC-rearranged sarcomas and 2 ATXN1-rearranged sarcomas were positive for MUC5AC, although the number of immunopositive cells was generally low (< 5%) in most samples, representing a characteristic scattered pattern. The only MUC5AC-negative case had the lowest tumor volume. Among the 110 mimicking round cell malignancies, 12 tumors showed MUC5AC positivity, including occasional cases of synovial sarcoma and small cell carcinoma, whereas the remaining 98 samples were negative. Despite its lower specificity than that of ETV4 and sparse reactivity that requires careful interpretation, MUC5AC may serve as a useful marker for CIC/ATXN1-rearranged sarcoma because of its wider accessibility.

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.

RE.GA.IN.: the Real-world Gastritis Initiative-updating the updates

At the end of the last century, a far-sighted 'working party' held in Sydney, Australia addressed the clinicopathological issues related to gastric inflammatory diseases. A few years later, an international conference held in Houston, Texas, USA critically updated the seminal Sydney classification. In line with these initiatives, Kyoto Global Consensus Report, flanked by the Maastricht-Florence conferences, added new clinical evidence to the gastritis clinicopathological puzzle.The most relevant topics related to the gastric inflammatory diseases have been addressed by the Real-world Gastritis Initiative (RE.GA.IN.), from disease definitions to the clinical diagnosis and prognosis. This paper reports the conclusions of the RE.GA.IN. consensus process, which culminated in Venice in November 2022 after more than 8 months of intense global scientific deliberations. A forum of gastritis scholars from five continents participated in the multidisciplinary RE.GA.IN. consensus. After lively debates on the most controversial aspects of the gastritis spectrum, the RE.GA.IN. Faculty amalgamated complementary knowledge to distil patient-centred, evidence-based statements to assist health professionals in their real-world clinical practice. The sections of this report focus on: the epidemiology of gastritis; Helicobacter pylori as dominant aetiology of environmental gastritis and as the most important determinant of the gastric oncogenetic field; the evolving knowledge on gastric autoimmunity; the clinicopathological relevance of gastric microbiota; the new diagnostic horizons of endoscopy; and the clinical priority of histologically reporting gastritis in terms of staging. The ultimate goal of RE.GA.IN. was and remains the promotion of further improvement in the clinical management of patients with gastritis.

[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.

Decreased expression of TFF2 and decreased αGlcNAc glycosylation are malignant biomarkers of pyloric gland adenoma of the duodenum

Pyloric gland adenoma (PGA) is a duodenal neoplasm expressing MUC6 and is often associated with high-grade dysplasia and adenocarcinoma. MUC6 secreted from the pyloric gland cells carries unique O-glycans exhibiting terminal α1,4-linked N-acetylglucosamine residues (αGlcNAc). The small peptide trefoil factor 2 (TFF2) is also secreted from pyloric gland cells and binds to αGlcNAc. We recently demonstrated that αGlcNAc serves as a tumor suppressor for gastric neoplasm including PGA, but the significance of TFF2 expression remains unknown. We examined 20 lesions representing low- and high-grade PGA in 22 cases by immunohistochemistry for αGlcNAc, TFF2, MUC6, MUC5AC, MUC2 and p53. αGlcNAc, TFF2 and MUC6 were co-expressed on the cell surface and a dot-like pattern in the cytosol in low-grade PGA lesions. High-grade PGA also expressed MUC6, but reduced αGlcNAc and TFF2 expression. The ratios of αGlcNAc or TFF2 to MUC6 score in high-grade PGA were significantly lower than low-grade PGA (P < 0.001). Co-expression of αGlcNAc-glycosylated MUC6 and TFF2 in PGA suggests the existence of αGlcNAc/TFF2 form complex in PGA cells, a finding consistent with our observations in non-neoplastic Brunner's gland cells. The decreased αGlcNAc and TFF2 expression are associated with high grade atypical cells, indicative of the malignant potential of PGA.

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.

Endoscopic diagnosis and treatment of superficial non-ampullary duodenal epithelial tumors: A review

The surface of the small bowel mucosa is covered more than any other section of the digestive canal; however, the overall prevalence of small bowel tumors of the whole gastrointestinal tract is evidently low. Owing to the improvement in endoscopic techniques, the prevalence of small bowel tumors has increased across multiple countries, which is mainly due to an increase in duodenal tumors. Superficial non-ampullary duodenal epithelial tumors (SNADETs) are defined as tumors originating from the non-ampullary region in the duodenum that share similarities and discrepancies with their gastric and colorectal counterparts in the pathogenesis and clinicopathologic characteristics. To date, white light endoscopy (WLE) remains the cornerstone of endoscopic diagnosis for SNADETs. Besides, narrow-band imaging (NBI) techniques and magnifying endoscopy (ME) have been widely used in the clinic and endorsed by multiple guidelines and consensuses for SNADETs' evaluation. Confocal laser endomicroscopy (CLE), endocytoscopy (ECS), and artificial intelligence (AI) are also up-and-coming methods, showing an exceptional value in the diagnosis of SNADETs. Similar to the endoscopic treatment for colorectal polyps, the choices for SNADETs mainly include cold snare polypectomy (CSP), endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and laparoscopic endoscopic cooperative surgery (LECS). However, owing to the narrow lumen, rich vascularity, weak muscle layer, abundant Brunner's gland, and the hardship of endoscope control, the duodenum ranks as one of the most dangerous operating areas in the digestive tract. Therefore, endoscopists must anticipate the difficulties in endoscopic maneuverability, remain aware of the increased risk of complications, and then select the appropriate treatment according to the advantages and disadvantages of each method.

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.

The Morphologic Spectrum of Gastric Type 1 Enterochromaffin-Like Cell Neuroendocrine Tumors

Although most well-differentiated gastric neuroendocrine tumors (gNETs) arise from enterochromaffin-like (ECL) cells in patients with autoimmune metaplastic atrophic gastritis (AMAG), the morphologic spectrum of these type 1 ECL-cell gNETs is not well defined. The extent of metaplastic progression in the background mucosa of AMAG patients with gNETs is likewise unclear. Here we report the histomorphology of 226 gNETs, including 214 type 1 gNETs (78 cases from 50 AMAG patients) pooled from a population with high AMAG prevalence. Most type 1 gNETs were ≤1.0 cm, of low grade, and multifocal, consistent with the results of previous reports. However, a high proportion (70/214, 33%) displayed unusual gNET morphologies not previously appreciated in AMAG patients. Unlike other type 1 gNETs with conventional neuroendocrine tumor morphologies, unconventional type 1 gNETs displayed cribriform networks of atrophic cells embedded within myxoid matrix (secretory-cribriform variant, 59%), sheets of deceptively bland discohesive cells resembling inflammatory infiltrates (lymphoplasmacytoid variant, 31%), or wreath-like arrangements of columnar cells wrapped around collagenous cores (pseudopapillary variant, 14%). Another unusual feature was that unconventional gNETs grew laterally within the mucosa (50/70, 71%) and were only rarely sampled from the submucosa (3/70, 4%). These features also differed from the conspicuous radial nodules (99/135, 73%) and frequent submucosal involvement (57/135, 42%) observed for conventional gNETs (P < .0001). Irrespective of morphology, type 1 gNETs were nearly always detected at first AMAG diagnosis (45/50, 90%) and tended to persist thereafter (34/43, 79%), despite similar clinical symptoms and laboratory values between AMAG patients with gNETs and those without. However, unlike AMAG patients without gNETs (n = 50), the background mucosa in patients with gNETs (n = 50) had already progressed to the morphologic equivalent of end-stage metaplasia (P < .0001). This included diffuse loss of parietal cells (92% vs 52%), complete intestinal metaplasia (82% vs 40%), and pancreatic metaplasia (56% vs 6%). Thus, type 1 ECL-cell gNETs are morphologically heterogeneous with a high prevalence of unconventional gNET morphologies. They tend to present silently at first AMAG diagnosis as multifocal lesions that persist within fields of mature metaplasia.

A case of pyloric gland adenoma with high-grade dysplasia in the duodenum arising from heterotopic gastric mucosa observed over 5 years

Pyloric gland adenoma (PGA) in the duodenum is a rare gastric phenotype duodenal neoplasm. Although heterotopic gastric mucosa in the duodenum has been recognized as a benign lesion, it is a potential precursor of PGA and gastric phenotype adenocarcinoma. Herein, we present a case follow-up of endoscopic and histological changes in the PGA in the duodenum from low-grade to high-grade dysplasia. PGA was considered to arise from the heterotopic gastric mucosa, because the heterotopic gastric mucosa was observed in the initial examination. It is difficult to distinguish heterotopic gastric mucosa from PGAs, both endoscopically and histologically. This increase in size may be useful for their differentiation. Therefore, endoscopists should not underestimate the growth of the heterotopic gastric mucosa compared to that in the previous examination.

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.

Sporadic and Familial Adenomatous Polyposis-associated Foveolar-type Adenoma of the Stomach

Gastric foveolar-type adenoma (FA) is a rare benign neoplasm occurring either sporadically or in patients with familial adenomatous polyposis (FAP). However, the molecular features of FA and the relationship between sporadic and syndromic lesions remain unclear. In this study, we performed clinicopathological, immunohistochemical, and genetic analyses of 18 sporadic and 30 FAP-associated FAs. Most sporadic and FAP-associated FAs were located in the upper or middle third of the stomach, on a background of fundic gland mucosa. Most lesions were low-grade, but 3 lesions had a high-grade component. Sporadic FAs included 2 morphologically distinct subtypes, that is, flat and raspberry-like FAs, which we distinguished based on the endoscopic features. Seven lesions were regarded as flat FAs, appearing as large, slightly elevated lesions and measuring 11 to 87 mm in size. Conversely, 10 raspberry-like FAs were small bright-red polyps, measuring 2 to 8 mm in size. FAP-associated FAs, particularly larger lesions, exhibited morphologic features resembling flat FAs but varied significantly in size (2 to 103 mm). Mutation analysis identified APC and KRAS mutations in all flat FAs but never in raspberry-like FAs. Remarkably, somatic APC and KRAS mutations were also detected in 19 (63%) and 27 (90%) of FAP-associated FAs, respectively. This indicates that they are genetically equivalent to sporadic, flat FAs. This study showed that sporadic FA includes at least 2 morphologically and genetically distinct subtypes: flat and raspberry-like FA. Furthermore, flat FA represents a sporadic counterpart of FAP-associated FA.

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.

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.

Histologic heterogeneity and syndromic associations of non-ampullary duodenal polyps and superficial mucosal lesions

BACKGROUND

Duodenal polyps and superficial mucosal lesions (DP/SMLs) are poorly characterised.

AIMS

To describe a series of endoscopically-diagnosed extra-ampullary DPs/SMLs.

METHODS

This is a retrospective study conducted in a tertiary referral Endoscopy Unit, including patients who had DPs or SMLs that were biopsied or removed in 2010-2019. Age, gender, history of familial polyposis syndromes, DP/SML characteristics were recorded. Histopathological, immunohistochemical and molecular analyses were performed.

RESULTS

399 non-ampullary DP/SMLs from 345 patients (60.6% males; median age 67 years) were identified. Gastric foveolar metaplasia represented the most frequent histotype (193 cases, 48.4%), followed by duodenal adenomas (DAs; 77 cases, 19.3%). Most DAs (median size 6 mm) were sessile (Paris Is; 48%), intestinal-type (96.1%) with low-grade dysplasia (93.5%). Among syndromic DAs (23%), 15 lesions occurred in familial adenomatous polyposis 1, two were in MUTYH-associated polyposis and one was in Peutz-Jeghers syndrome (foveolar-type, p53-positive, low-grade dysplasia). Only one (3.3%) tubular, low-grade DA showed mismatch repair deficiency (combined loss of MLH1 and PMS2, heterogeneous MSH6 expression), and it was associated with a MLH1 gene germline mutation (Lynch syndrome).

CONCLUSION

DPs/SMLs are heterogeneous lesions, most of which showing foveolar metaplasia, followed by low-grade, intestinal-type, non-syndromic DAs. MMR-d testing may identify cases associated with Lynch syndrome.

Small Intestinal Adenocarcinomas Arising in Enteritis Cystica Profunda With Metaplasia: A Report of 2 Cases

Enteritis cystica profunda (ECP) is an uncommon benign condition arising after mucosal damage. We describe 2 cases of small intestinal adenocarcinomas associated with ECP at the distal ileum, one in a background of active Crohn ileitis (case 1), the other 22 years after pelvic radiation therapy (case 2). Both patients presented with small bowel obstruction and received ileocectomy. Macroscopic examination identified an indurated/strictured area in the distal ileum. Histologically, both cases showed a low-grade tubuloglandular adenocarcinoma arising in a background of chronic ischemic stricture and ECP lined by flat cuboidal cells with mild cytologic atypia resembling pancreatobiliary-type epithelium. There was no conventional dysplasia in the surface or adjacent mucosa. Immunohistochemically, both ECP with metaplasia and invasive carcinomas were diffusely positive for CK7 and CK19, while focally positive for CDX2 or CK20. Both cases showed normal wild-type p53 expression. Case 2 was also mismatch repair protein proficient, with membranous β-catenin staining, and retained nuclear SMAD4 expression. In summary, the 2 cases uniquely exhibits "enteritis-metaplasia-carcinoma" sequence, which has not been reported before. This process appears to bypass conventional dysplasia, be slow and indolent, independent of p53, APC/β-catenin, and SMAD4/TGFβ signaling pathways.

APC mutations are common in adenomas but infrequent in adenocarcinomas of the non-ampullary duodenum

BACKGROUND

Recent studies highlighted the clinicopathological heterogeneity of non-ampullary duodenal adenomas and adenocarcinomas, but the detailed process of the malignant transformation remains unclear.

METHODS

We analyzed 144 adenomas and 54 adenocarcinomas of the non-ampullary duodenum for immunohistochemical phenotypes, genetic alterations, and mismatch repair (MMR) status to probe their histogenetic relationship.

RESULTS

The median ages of patients with adenoma and adenocarcinoma were the same (66 years). Adenomas were histologically classified as intestinal-type adenoma (n = 124), pyloric gland adenoma (PGA, n = 10), gastric-type adenoma, not otherwise specified (n = 9), and foveolar-type adenoma (n = 1). Protein-truncating APC mutations were highly frequent in adenomas (85%), with the highest prevalence in intestinal-type adenomas (89%), but rare in adenocarcinomas (9%; P = 2.1 × 10^-23). Close associations between phenotypic marker expression and genetic alterations were observed in adenomas, but not in adenocarcinomas, excluding the common association between GNAS mutations and MUC5AC expression. MMR deficiency was more frequent in adenocarcinomas (20%) than in adenomas (1%; P = 2.6 × 10^-6). One MMR-deficient adenoma and three MMR-deficient adenocarcinomas occurred in patients with Lynch syndrome. Additionally, three other patients with an MMR-deficient adenocarcinoma fulfilled the revised Bethesda criteria.

CONCLUSION

The discrepant APC mutation frequency between adenomas and adenocarcinomas suggests that APC-mutated adenomas, which constitute the large majority of non-ampullary duodenal adenomas, are less prone to malignant transformation. Non-ampullary duodenal adenocarcinomas frequently exhibit MMR deficiency and should be subject to MMR testing to determine appropriate clinical management, including the identification of patients with Lynch syndrome.

Feline pyloric and duodenal adenoma: A histological and immunohistochemical study

Although pyloric and duodenal adenomas occasionally occur in cats, limited information is currently available on their phenotypes and molecular features. The present study investigated the pathological features of these tumors and the mechanisms underlying their tumorigenesis. Biopsy samples from 8 cats diagnosed with pyloric or duodenal adenomas were examined by histopathology and immunohistochemistry. Normal pyloric and duodenal tissues of cats were assessed for comparison. All cases showed a papillary growth of cuboidal to columnar cells with eosinophilic, ground-glass cytoplasm. Mucin in tumor cells was positive for periodic acid-Schiff and paradoxical concanavalin-A staining, but was negative for Alcian blue. Immunohistochemically, tumor cells were positive for cytokeratin (CK) 19 in 8/8 cases and for CK20 in 5/8 cases, and weakly positive for CD10 in 4/8 cases, CK7 in 3/8 cases, and β-catenin in 2/8 cases. Nuclear accumulation of p53 was not detected in any case. DNA sequencing analysis identified no KRAS or GNAS mutations in the 4/8 cases and 5/8 cases for which the KRAS and GNAS genes could be amplified. The histological and immunohistochemical features of tumor cells were similar to those of mucous neck cells and the pyloric gland of normal feline tissue. The morphology of feline pyloric and duodenal adenomas was consistent with that of pyloric gland adenoma in humans; however, its molecular pathogenesis may differ given the lack of KRAS and GNAS mutations in the feline tumors.

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.

Small Bowel Epithelial Precursor Lesions: A Focus on Molecular Alterations

The wider use of gastrointestinal endoscopic procedures has led to an increased detection of small intestinal preneoplastic and neoplastic epithelial lesions, most of which are identified in the duodenum and ampullary region. Like their malignant counterparts, small intestinal glandular precursor lesions, which include adenomas and hamartomas, may arise sporadically or be associated with hereditary tumor syndromes, such as familial adenomatous polyposis, MUTYH-associated polyposis, Lynch syndrome, Peutz-Jeghers syndrome, juvenile polyposis syndrome, and Cowden syndrome. In addition, dysplastic, preinvasive lesions have been observed adjacent to small bowel adenocarcinomas complicating immune-related disorders, such as celiac or Crohn's disease. Adenomatous lesions may exhibit an intestinal-type, gastric-type, or, very rarely, serrated differentiation, related to different molecular pathogenetic mechanisms. Finally, in the background of multiple endocrine neoplasia 1 syndrome, precursor neuroendocrine growths have been described. In this review we offer a comprehensive description on the histo-molecular features of the main histotypes of small bowel epithelial precursors lesions, including: (i) sporadic adenomas (intestinal-type and gastric-type; non-ampullary and ampullary); (ii) syndromic adenomas; (iii) small bowel dysplasia in celiac and Crohn's disease; (iv) serrated lesions; (v) hamartomatous lesions; and (vi) neuroendocrine precursor lesions.

Large duodenal pyloric gland adenoma successfully resected by endoscopic submucosal dissection

A 71-year-old woman was given a barium meal examination as part of a workup for recurring melena and iron deficiency anemia (IDA), and it revealed a large duodenal polyp measuring 60 mm in diameter. Subsequent upper gastrointestinal endoscopy showed a large pedunculated polyp in the duodenal bulb. Magnifying endoscopy with narrow-band imaging (NBI) showed that the lesion consisted of a regular enlarged intervening part between crypts of the epithelium that resembled gastric mucosa. Although the lesion was suspected of being benign, it was resected by endoscopic submucosal dissection (ESD) to prevent the progression of the IDA. The pathology examination revealed the proliferation of mildly irregular-shaped or dilated glands lined by cuboidal cells and low columnar cells in the submucosa. The gastric glands were immunohistochemically positive for MUC6, suggesting pyloric gland differentiation. The lesion was covered by a foveolar-type epithelium, and we made a diagnosis of pyloric gland adenoma (PGA). PGAs are most common in the stomach, and they are rare in the duodenum, where endoscopic treatment is technically challenging. Here we report a case of large duodenal PGA successfully resected by ESD. Since part of PGAs has been reported to be associated with adenocarcinoma, minimally invasive treatment strategies are desirable to reduce the risk of progression to carcinoma.

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.

Helicobacter Infection and Gastric Adenoma

Background: We aimed to provide insight into the actual frequencies of gastric adenoma types and their association with gastritis status and associated mucosal changes with a focus on Helicobacter infection and the operative link on gastritis assessment (OLGA)/operative link on gastric intestinal metaplasia assessment (OLGIM) staging. Methods: From the archive of the Institute of Pathology in Bayreuth, we collected a consecutive series of 1058 gastric adenomas diagnosed between 1987 and 2017. Clinicopathological parameters retrieved from diagnostic reports included adenoma type and localization, associated mucosal changes in antrum and corpus (i.e., type of gastritis, the extent of intestinal metaplasia and atrophy), gender, date of birth, and date of diagnosis. Results: Intestinal-type adenoma was the most frequent adenoma (89.1%), followed by foveolar-type adenoma (4.3%), pyloric gland adenoma (3.4%), adenomas associated with hereditary tumor syndromes (2.8%), and oxyntic gland adenoma (0.4%). Adenomas were found in the background of Helicobacter pylori (H. pylori) gastritis in 23.9%, Ex-H. pylori gastritis in 36.0%, autoimmune gastritis in 24.8%, chemical reactive gastritis in 7.4%, and others in 0.1%. More than 70% of patients with gastric adenomas had low-risk stages in OLGA and OLGIM. Conclusions: We found a higher frequency of foveolar-type adenoma than anticipated from the literature. It needs to be questioned whether OLGA/OLGIM staging can be applied to all patients.

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.

Cell polarity (the 'four lines') distinguishes gastric dysplasia from epithelial changes in reactive gastropathy

AIMS

Gastric dysplasia is a risk factor for synchronous and subsequent gastric carcinoma. Distinguishing gastric dysplasia from reactive changes is subject to interobserver disagreement and is a frequent reason for expert consultation. We previously used assessment of surface cell polarity (the 'four lines') as a key feature to decrease equivocal diagnoses in Barrett oesophagus. In the current study, we examined for the presence or absence of the four lines in gastric dysplasia and reactive gastropathy.

MATERIALS AND METHODS

The study includes all (n = 91) in-house biopsies with at least gastric dysplasia from the surgical pathology archives of two academic institutions during a 5-year period from 2008 to 2012. A reactive gastropathy group (n = 60) was created for comparison.

RESULTS

The dysplasia/neoplasia group was comprised of 14 biopsies of gastric foveolar-type dysplasia, 59 of intestinal-type dysplasia, 14 with dysplasia in fundic gland polyps, three pyloric gland adenomas and one oxyntic gland adenoma. Loss of surface cell polarity was seen in all 88 dysplasia cases with evaluable surface epithelium. All 57 reactive gastropathy cases with evaluable surface epithelium showed intact surface cell polarity except in focal areas directly adjacent to erosions in 17 cases, where the thin wisp of residual surface mucin could not be appreciated on haematoxylin and eosin.

CONCLUSION

Surface cell polarity (the four lines) was lost in all gastric dysplasia biopsies with evaluable surface epithelium and maintained in all biopsies of reactive gastropathy. Caution should be taken in using this feature adjacent to erosions in reactive gastropathy.

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.

The clinicopathological and molecular features of sporadic gastric foveolar type neoplasia

Gastric intraepithelial foveolar type neoplasia (IEFN) is not well defined. In addition, atrophic mucosa (AM) is an important issue to consider when evaluating gastric tumorigenesis. Here, we assessed the clinicopathological characteristics and molecular alterations contributing to the development of IEFN compared with intestinal type neoplasia. We examined the clinicopathological and molecular features of 42 cases of IEFN with low-grade dysplasia (LGD) and those of 77 cases of intraepithelial intestinal type neoplasia (IEIN) with LGD. The clinicopathological and molecular features examined included the AM status, mucin phenotype expression, CDX2 expression, p53 overexpression, β-catenin intranuclear accumulation, microsatellite instability (MSI), DNA methylation status (low methylation epigenotype [LME], intermediate ME, or high ME), allelic imbalances (AIs), and APC promoter 1B mutations. There were no differences in the frequencies of AM and rates of CDX2 expression between IEFN and IEIN cases. Although no differences in the frequencies of p53 overexpression and MSI were observed between the two histological types, intranuclear expression of β-catenin was significantly higher in IEIN than in IEFN. In addition, although the rate of LME was significantly higher in IEFN cases than in IEIN cases, IEFN was characterized by AIs at multiple foci. Finally, mutation of the APC promoter 1B, which is a characteristic of gastric adenocarcinoma and proximal polyposis of the stomach (potentially resembling IEFN), was detected in only one IEFN case. These findings suggested that IEFN may be an independent entity in terms of molecular alterations including the presence of multiple AIs and LME.

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.

[Full thickness resection of a pyloric adenoma in the proximal duodenum in a 67-year-old patient with attenuated polyposis coli]

BACKGROUND

 Pyloric gland adenomas (PGAs) are very rare and underdiagnosed, mostly be founded in the stomach. Similar to colorectal adenomas they have a high risk of malignant transformation to adenocarcinoma up to 12-47 %. Endoscopic resections in the duodenum harbor a significant risk of complications. EMR is the current standard technique for treatment of duodenal non-ampullary adenomas. Complete resection rates are considerably high at about 90 %. Adverse events as bleeding was reported up to 25 %. ESD is not recommended for resection of duodenal lesions since the perforation rate may be as high as 35 %. Use of EFTR in the duodenum are limited to a single case study of 20 patients.

CASE

 A 67 year old patient with attenuated polyposis coli presented for screening. Gastroscopy showed a 20 mm large, non-ampullary lesions in the proximal duodenum (pars I). The margins of the duodenal lesions were marked with a high-frequency (HF) probe. An integrated balloon dilatation (20 mm) of the upper esophageal sphincter and the pylorus was performed to facilitate advancing of the gastroduodenal FTRD^® (Ovesco Endoscopy AG). After pulling the duodenal lesion into the cap with a grasper the FTRD clip was deployed and the lesion immediately resected with the preloaded snare. A single-shot antibiotic prophylaxis with 2 g ceftriaxone i. v. was administered during the intervention. Second-look endoscopy was scheduled 24 h after resection. The resectat showed histologically a gastric type adenoma of 18 mm in the proximal duodenum (immunohistochemistry positive for Mucin-1, Mucin-5, Mib 1).

CONCLUSION

 Herein we present the first case of duodenal EFTR in a patient with attenuated FAP and a PGA. There are currently no specific guidelines for the removal and surveillance. ASGE recommends resection and surveillance endoscopy at 3-5 years interval.

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.

Next-generation sequencing identifies 2 genomically distinct groups among pyloric gland adenomas

The molecular alterations identified among pyloric gland adenomas (PGAs) in the published literature are based on polymerase chain reaction of targeted genes, and next-generation sequencing (NGS) has not been performed. In this study, we performed NGS and correlated the molecular alterations with the histologic grade of dysplasia and immunohistochemical findings in a cohort of PGAs. Successful DNA extraction and sequencing were performed in 15 pyloric gland adenomas/adenocarcinoma from 12 patients. Additionally, 4 specimens of autoimmune gastritis were selected to serve as the control group. Ten PGAs with low-grade dysplasia were seen to have mutations in the triad of APC, KRAS, and GNAS genes. Five PGAs with high-grade dysplasia/adenocarcinoma exhibited mutations in several genes including APC, CTNNB1, KRAS, GNAS, TP53, CDKN2A, PIK3CA, and EPHA5 genes but did not exhibit mutations in the triad of APC, KRAS, and GNAS genes. The median tumor mutational burden was higher in PGAs with high-grade dysplasia/adenocarcinoma when compared with PGAs with low-grade dysplasia (5.25 and 4.38, respectively). PGAs with high-grade dysplasia/adenocarcinoma had more chromosomal gains and losses than PGAs with low-grade dysplasia. The molecular findings suggest that there are 2 separate mutator pathways of dysplasia development in PGAs.

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.

Autoimmune Gastritis: An Underappreciated Entity

Autoimmune gastritis is a relatively common but likely underdiagnosed form of chronic gastritis that is associated with iron-deficiency anemia as well as vitamin B12/cobalamin deficiency. This disease confers a 13-fold increased risk of gastric well-differentiated neuroendocrine tumors, due to persistently elevated gastrin levels, and a 3- to 7-fold increased risk of gastric adenocarcinoma. The case described here has a typical presentation of the disease, and the following review highlights key histologic features that aid in the identification of this inflammatory process. Additionally, background information on ancillary testing and mechanisms of disease are discussed with a focus on details most useful for the pathologist who is presented with the opportunity to make this often unexpected but medically significant diagnosis.

Duodenal Epithelial Polyps: A Clinicopathologic Review

CONTEXT.—

Duodenal epithelial polyps are reported in 1.5% to 3% of individuals referred for upper endoscopy. Most duodenal epithelial polyps are asymptomatic and nonneoplastic; however, a small subset is neoplastic and may progress to adenocarcinoma. Recent advances in immunohistochemical and molecular techniques have helped further characterize these polyps, shedding light on their origin, classification, and risk of progression to adenocarcinoma.

OBJECTIVE.—

To provide a comprehensive clinicopathologic review of nonneoplastic and neoplastic duodenal epithelial polyps, with particular emphasis on recent developments in classification schemes and risk stratification based upon immunohistochemical and molecular profiles.

DATA SOURCES.—

This review is based on peer-reviewed literature and the authors' experiences.

CONCLUSIONS.—

In this review we provide an update on the clinicopathologic, immunohistochemical, and molecular features of duodenal epithelial polyps and discuss the surveillance recommendations and treatment options available. Particular attention should be placed on recognizing duodenal adenomas with intestinal, gastric, and serrated phenotype, as they have an increased risk of malignant transformation if not completely excised.

Clinicopathological Features and Magnifying Chromoendoscopic Findings of Non-Ampullary Duodenal Epithelial Tumors

BACKGROUND AND AIMS

We aimed to investigate an association between clinicopathological features, including immunohistochemical mucin phenotypes, and magnifying chromoendoscopic findings with crystal violet staining (ME-CV) in non-ampullary duodenal epithelial tumors (NADETs).

METHODS

A total of 55 patients with NADET were divided into 3 groups by mucin phenotype: intestinal, gastrointestinal, or gastric. ME-CV findings were classified into 4 patterns: convoluted, leaf-like, reticular/sulciolar, and pinecone. The clinicopathological features and ME-CV findings were compared among the mucin phenotypes.

RESULTS

Tumors of the gastric type were located in the duodenal bulb (p < 0.001), and contained pyloric gland adenoma (p < 0.001) more frequently than the other types. White-light endoscopy indicated that milk-white mucosa was less frequent in tumors of the gastric type than in those of the gastrointestinal type (p = 0.006) and the intestinal type (p < 0.001). ME-CV findings were significantly different between the gastric type and the other type (p = 0.028). Totally, 5 of 8 tumors of the gastric type manifested a pinecone pattern, 4 of which were compatible with pyloric gland adenoma.

CONCLUSIONS

The endoscopic findings of NADETs differ according to mucin phenotype. A pinecone pattern under ME-CV may be characteristic of NADETs of the gastric type, especially pyloric gland adenoma.

Duodenal Pyloric Gland Adenoma in a 59-Year-Old Asian Male

Pyloric gland adenomas (PGAs) are rare precancerous tumors typically arising from the stomach. Even more rarely do they arise in extragastric sites such as the duodenum and gallbladder. The identification of PGAs is important because they possess a risk of developing into invasive adenocarcinoma. This case report describes a 59-year-old male who presented to our office for a follow-up of a nonspecific duodenal lesion. Endoscopic ultrasound and pathology revealed a PGA with low grade dysplasia and some areas of focal high grade dysplasia. It is important that gastroenterologists are aware of these lesions and their risk of malignant transformation. More studies are needed to describe the long-term behavior of pyloric gland adenomas and to recommend appropriate endoscopic surveillance of these lesions.

Molecular and Pathological Features of Gastric Cancer in Lynch Syndrome and Familial Adenomatous Polyposis

Lynch syndrome (LS) and familial adenomatous polyposis (FAP) are autosomal dominant hereditary diseases caused by germline mutations leading to the development of colorectal cancer. Moreover, these mutations result in the development of a spectrum of different tumors, including gastric cancers (GCs). Since the clinical characteristics of GCs associated with LS and FAP are not well known, we investigated clinical and molecular features of GCs occurring in patients with LS and FAP attending our Institution. The Hereditary Tumor Registry was established in 1994 at the Department of Oncologic Gastroenterology, CRO Aviano National Cancer Institute, Italy. It includes 139 patients with LS and 86 patients with FAP. Patients were recruited locally for prospective surveillance. Out of 139 LS patients, 4 developed GC—3 in the presence of helicobacter pylori infection and 1 on the background of autoimmune diseases. All GCs displayed a high microsatellite instability (MSI-H) and loss of related mismatch repair (MMR) protein. One of the FAP patients developed a flat adenoma, displaying low-grade dysplasia at the gastric body, and another poorly differentiated adenocarcinoma with signet ring cells like Krukenberg without HP infection. LS carriers displayed a risk of GC. The recognition of HP infection and autoimmune diseases would indicate those at higher risk for an endoscopic surveillance. Regarding FAP, the data suggested the need of suitable endoscopic surveillance in long survivals with diffuse fundic gland polyps.

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

AIMS

There is limited information regarding the clinicopathological and immunohistochemical characteristics of gastric pyloric gland adenomas (PGAs).

METHODS AND RESULTS

Sixty-seven cases of gastric PGA from 57 patients were analysed. PGAs occurred with similar frequency in men and women (47.4 and 52.6%, respectively), with a mean age of 66 years. Most presented in the gastric body/fundus (67.2%). Fifteen cases (22.4%) developed against a background of autoimmune gastritis (AIG), whereas normal mucosa was seen in 35.8%. Only 16.4% (11 cases) developed in patients with a genetic predisposition, most commonly familial adenomatous polyposis. Low-grade lesions had a mean size of 1.5 cm, while PGAs with high-grade dysplasia (HGD) or adenocarcinoma had a mean size of 3.5 cm (P < 0.001) and more commonly showed tubulovillous architecture (50.0 versus 25.6% in low-grade dysplasia; P = 0.040). Most PGAs (61.2%) co-expressed mucin (MUC)5AC and MUC6 (mixed type), which was associated significantly with HGD or adenocarcinoma (P = 0.013). AIG was also associated with HGD (P = 0.027), but genetic predisposition did not correlate with the grade of dysplasia (P = 0.793). The recurrence rate of PGA was similar for high- (11.8%) and low-grade lesions (7.4%) (P = 0.624).

CONCLUSIONS

The risk of HGD increases with the size of PGA, tubulovillous architecture and the presence of AIG as well as mixed immunophenotype. As the overall local recurrence rate is less than 10%, PGAs may be treated conservatively, but they should be excised completely if possible, particularly if they are large or show high-grade features.

Familial Adenomatous Polyposis with Multiple Helicobacter-negative Early Gastric Cancers Treated by Endoscopic Submucosal Dissection

Stomach cancer rarely develops in patients with familial adenomatous polyposis (FAP), and Helicobacter pylori infection may increase the risk of FAP-related gastric cancer. We describe the case of a 64-year-old woman who developed multiple synchronous early gastric cancers without H. pylori infection. Nine cancer lesions were successfully treated by endoscopic submucosal dissection. An immunohistochemical analysis revealed that the tumors were positive for mucin (MUC)2, MUC6, and CDX2, but negative for MUC5AC, suggesting that the tumors were gastrointestinal mixed type. Periodical endoscopic surveillance is important for the detection of cancers at an early stage.