Usefulness of the 'cosmos pattern' for differentiating between cervical gastric-type mucin-positive lesions and other benign cervical cystic lesions in magnetic resonance images.

AIM: To evaluate the usefulness of the 'cosmos pattern' (CP) on magnetic resonance (MR) images for differentiating between gastric-type mucin-positive lesions (GMPL) and gastric-type mucin-negative lesions (GMNL). METHODS: This study included 131 patients with clinical suspicion of lobular endocervical glandular hyperplasia (LEGH) who underwent pelvic MR imaging and a Pap smear and/or latex agglutination assay. Differences in MR findings, such as cyst and solid component patterns, cervical location and T1-weighted image (T1WI) signal intensity, were compared between GMPL and GMNL. The diagnostic performances of the findings were assessed. RESULTS: The frequencies of CP (63.1%), upper part (UP) lesions (72.3%) and hypointense area compared with the cervical stroma on T1WI (61.3%) were significantly greater in GMPL than in GMNL (P < 0.05). The sensitivity, specificity, positive predictive value, negative predictive value and odds ratio of the CP for diagnosis of GMPL were 63.1%, 87.9%, 83.7%, 70.7% and 12.4, respectively. In GMNL, a 'macrocystic pattern' was observed in 65.2% of patients; an isointense or hyperintense area on T1WI was observed in 86.4% of patients. The sensitivity was highest (90.8%) when one or more of the following were observed: CP, UP lesion, or hypointense area on T1WI. The specificity was highest (95.5%) when the CP was observed as a hypointense area on T1WI. CONCLUSION: The CP is a highly specific finding for diagnosis of GMPL. If the CP is observed as a hypointense area compared with the cervical stroma on T1WI, GMPL (i.e., LEGH or gastric-type mucinous carcinoma) should be strongly suspected.

Structural diversity of human gastric mucin glycans.

The mucin O-glycosylation of 10 individuals with and without gastric disease was examined in depth in order to generate a structural map of human gastric glycosylation. In the stomach, these mucins and their O-glycosylation protect the epithelial surface from the acidic gastric juice and provide the first point of interaction for pathogens such as Helicobacter pylori, reported to cause gastritis, gastric and duodenal ulcers and gastric cancer. The rational of the present study was to map the O-glycosylation that the pathogen may come in contact with. An enormous diversity in glycosylation was found, which varied both between individuals and within mucins from a single individual: mucin glycan chain length ranged from 2-13 residues, each individual carried 34-103 O-glycan structures and in total over 258 structures were identified. The majority of gastric O-glycans were neutral and fucosylated. Blood group I antigens, as well as terminal α1,4-GlcNAc-like and GalNAcß1-4GlcNAc-like (LacdiNAc-like), were common modifications of human gastric O-glycans. Furthemore, each individual carried 1-14 glycan structures that were unique for that individual. The diversity and alterations in gastric O-glycosylation broaden our understanding of the human gastric O-glycome and its implications for gastric cancer research and emphasize that the high individual variation makes it difficult to identify gastric cancer specific structures. However, despite the low number of individuals, we could verify a higher level of sialylation and sulfation on gastric O-glycans from cancerous tissue than from healthy stomachs.

Endoscopic and clinicopathological features of intramucosal, histologically mixed-type, low-grade, well-differentiated gastric tubular adenocarcinoma with the potential for late-onset lymph node metastasis.

BACKGROUND: Intramucosal, histologically mixed-type, low-grade (LG), well-differentiated gastric tubular adenocarcinomas (tub1s; LG-tub1s) have larger mean diameters and exhibit a higher frequency of the gastric mucin phenotype (G-phenotype) than pure LG-tub1s. In proportion to their increases in diameter, G-phenotype differentiated-type early gastric cancer (EGC) tumours reportedly grow to eventually contain (an) undifferentiated-type component(s) and LG-tub1s, which are included in differentiated-type EGCs, reportedly exhibit changes in their glandular architectural and cytological atypia grades from LG to high-grade (HG) and can grow to contain a moderately differentiated tubular adenocarcinoma (tub2) component and undifferentiated components. Because they generally show a higher frequency of malignancy relative to tumours with a higher atypia grade and lower differentiation degree, it is suggested that, among mixed-type LG-tub1s, G-phenotype LG-tub1s containing an HG-tub2 component (LG-tub1s > HG-tub2) with undifferentiated components might lead to late-onset metastasis to lymph nodes even after a successful endoscopic submucosal dissection (ESD). We aimed to clarify the endoscopic and clinicopathological features of these G-phenotype LG-tub1s > HG-tub2. METHODS: Of the 13,217 oesophagogastroduodenoscopies performed at our institutions between September 2008 and March 2016, 185 EGC lesions were evaluated in this retrospective observational study. Among these EGC lesions, 60 intramucosal LG-tub1s were divided into 53 tub1 (44 pure LG-tub1s and nine LG-tub1s containing HG-tub1) lesions and seven LG-tub1 > tub2 (LG-tub1 containing LG- and HG-tub2) lesions. RESULTS: The frequencies of the superficial depressed type (P = 0.026), reddish colour (P = 0.006), HG of contained tub2s (P = 0.006), and G-phenotype (P = 0.028) were significantly higher in the LG-tub1 > tub2 group than those in the tub1 group. However, the largest lesion of the LG-tub1 > tub2 group had a superficial flat appearance, an isochromatic colour, an HG-tub2 and an undifferentiated component, and a large diameter greater than 30 mm, and it exhibited a G-phenotype. CONCLUSIONS: Intramucosal G-phenotype LG-tub1s > HG-tub2 are potential premalignant stomach neoplasms that may have specific endoscopic and clinicopathological features. However, G-phenotype LG-tub1s > HG-tub2 with undifferentiated component, which potentially show higher malignancy than those without undifferentiated components might change from a reddish to isochromatic colour. Accurately diagnosing, treating, and following-up G-phenotype LG-tub1s > HG-tub2 might decrease the number of patients who experience late-onset metastasis after ESD.

Usefulness of a management protocol for patients with cervical multicystic lesions: A retrospective analysis of 94 cases and the significance of GNAS mutation.

AIM: The proper preoperative diagnosis and management of cervical proliferative disorders presenting with multiple cysts, including minimal deviation adenocarcinoma (MDA), lobular endocervical glandular hyperplasia (LEGH), and nabothian cyst (NC), have not been fully established. We previously proposed a management protocol comprising a diagnostic approach using cytology, magnetic resonance imaging, and gastric-type mucin and subsequent treatment. We herein evaluate the usefulness of this protocol and implications of GNAS mutations in LEGH. METHODS: The clinical courses of 94 patients with cervical multicystic lesions who visited our hospital between June 1995 and September 2014 were retrospectively analyzed. GNAS mutations were investigated in 10 LEGH, five LEGH with atypia, and two MDA cases. RESULTS: Of the 94 patients, the conditions of 10, 59, and 25 were clinically diagnosed as suspicious of MDA or carcinoma (S/O MDA-Ca), suspicious of LEGH (S/O LEGH), and NC, respectively. Ten patients each with S/O MDA-Ca and S/O LEGH underwent hysterectomy, and the correct ratio for diagnosis was 90% (18/20). Of the 42 S/O LEGH cases followed-up for more than 12 months, three showed an increase in tumor size. After hysterectomy, two were LEGH with atypia while one was NC. The GNAS mutation was detected in two cases of LEGH with atypia, one of which showed an increase in tumor size during follow-up. CONCLUSION: The management protocol we propose herein will be useful. An increase in tumor size is important to detect potentially malignant LEGH. GNAS mutations may be involved in the tumorigenesis of potentially malignant LEGH.

Alteration or adaptation, the two roads for human gastric mucin glycosylation infected by Helicobacter pylori.

Helicobacter pylori is a Gram-negative bacterium that colonizes the mucus niche of the gastric mucosa and infects more than half of the world's human population. Chronic infection may cause gastritis, duodenal ulcer, intestinal metaplasia or gastric cancer. In the stomach, H. pylori interacts with O-glycans of gastric mucins but the mechanism by which the bacteria succeed in altering the mucosa remains mainly unknown. To better understand the physiopathology of the infection, inhibitory adhesion assays were performed with various O-glycans expressed by human gastric mucins, and topographic expression of gastric mucins MUC5AC and MUC6 was analyzed for healthy uninfected individuals, for infected asymptomatic individuals and for patients infected by H. pylori and having the incomplete type of intestinal metaplasia. The glycosylation of the gastric mucosa of asymptomatic individuals infected by H. pylori was determined and compared with the glycosylation pattern found for patients with the incomplete type of intestinal metaplasia. Results show that H. pylori manages to modulate host's glycosylation during the course of infection in order to create a favorable niche, whereas asymptomatic infected individuals seem to counteract further steps of infection development by adapting their mucus glycosylation.

The lacdiNAc-specific adhesin LabA mediates adhesion of Helicobacter pylori to human gastric mucosa.

Adhesion of Helicobacter pylori to the gastric mucosa is a necessary prerequisite for the pathogenesis of H. pylori-related diseases. In this study, we investigated the GalNAcß1-4GlcNAc motif (also known as N,N'-diacetyllactosediamine [lacdiNAc]) carried by MUC5AC gastric mucins as the target for bacterial binding to the human gastric mucosa. The expression of LacdiNAc carried by gastric mucins was correlated with H. pylori localization, and all strains tested adhered significantly to this motif. Proteomic analysis and mutant construction allowed the identification of a yet uncharacterized bacterial adhesin, LabA, which specifically recognizes lacdiNAc. These findings unravel a target of adhesion for H. pylori in addition to moieties recognized by the well-characterized adhesins BabA and SabA. Localization of the LabA target, restricted to the gastric mucosa, suggests a plausible explanation for the tissue tropism of these bacteria. These results pave the way for the development of alternative strategies against H. pylori infection, using adherence inhibitors.

Pyloric gland adenoma: a histologic, immunohistochemical and molecular genetic study of 23 cases.

Pyloric gland adenoma is a rare neoplasm with a gastric epithelial differentiation. We report 23 cases of pyloric gland adenoma in older persons, with a mean age of 74 years (range 52 - 87 years). They occurred in the esophagus (3 cases), corporal gastric mucosa (7 cases), duodenum (10 cases), gallbladder (2 cases), and choledochus (one case). Histologically, they were characterized by closely packed pyloric gland-type tubules with a monolayer of cuboidal to low columnar epithelial cells containing basally located round nuclei, and a superficial layer of tall, columnar, foveolar-type epithelium. Immunohistochemically, most tumor glands expressed pyloric gland mucin MUC6, whereas MUC5AC was positive in superficial gastric foveolar epithelium, and in a minority of glands. In addition, scattered neuroendocrine cells positive for chromogranin A and/or synaptophysin were seen in all cases. In 3 cases (two cases in the gallbladder and one case in the esophagus), areas of intestinal metaplasia with CK20, CDX2, and MUC2 positivity were found. Focal low-grade dysplasia was found in five cases (21.7%), and diffuse high-grade dysplasia was seen in one adenoma (4.4%), i.e., 6 of 23 PGAs (26.1%) showed dysplastic features. In one esophageal case, an invasive adenocarcinoma was diagnosed. Scattered p53 positive cells were found in all cases. Their number was higher in lesions with low-grade dysplasia and it was substantially increased in adenoma with high-grade dysplasia and in adenocarcinoma. Our molecular genetic results indicate that pyloric gland adenomas neoplastic nature is associated with p53 accumulation, mutations in oncogenes GNAS, KRAS, CTTNB1 and tumor suppressor genes SMAD4, and TP53. Pyloric gland adenoma can evolve into dysplasia and adenocarcinoma.

Helicobacter pylori Infection and the Patterns of Gastric Mucin Expression in Children.

BACKGROUND: The updated model for the mechanism of gastric carcinogenesis demonstrates that Helicobacter pylori (H. pylori) is a risk factor in every step of the process. The expression of certain gastric mucins is altered by H. pylori infection in adult patients. The aim of our research was to assess the impact of H. pylori infection on the expression of secretory mucins in the pediatric antral mucosa. METHODS: Slides were stained with monoclonal antibodies for MUC5AC, MUC6 and MUC2, digitalized and scored using both a semiquantitative and a quantitative approach. RESULTS: The expression of MUC5AC was significantly lower in infected children. Also, MUC2 expression was more pronounced in infected children. MUC6 expression did not differentiate between infected and noninfected children. Additionally, the presence of chronic inflammation significantly altered the expression of MUC6 and MUC2. The expression of MUC6 was significantly higher in patients with gastric atrophy. CONCLUSION: The minor differences in mucin expression at distinct ages might stem from different H. pylori exposure periods. Further research is needed to determine the particular patterns of expression according to age and to evaluate the effects of the interaction between H. pylori and mucins in the progression of the gastric carcinogenesis cascade.

New algorithm to differentiate histochemical types of intestinal metaplasia: G&S2 method / Novo algoritmo para diferenciar tipos histoquímicos de metaplasia intestinal: G & Amp; Método S2

ABSTRACT Introduction The classification of intestinal metaplasia by histochemistry methods has been described as the most appropriate. However, current algorithms are not replicable in laboratories due to severe limitations. Objective To evaluate a new algorithm to differentiate histochemical types of intestinal metaplasia. Material and Method: Cross-sectional research in which 512 gastric biopsies with intestinal metaplasia (paraffin blocks) were evaluated by a new algorithm using two types of Alcian Blue dyes during February-March of 2020 in the pathological anatomy service of the Maria Auxiliadora Hospital, Lima, Peru. This evaluation consisted of two steps: visualization of acid mucins in the columnar cells of the gastric mucosa and calculation of the weighted Kappa statistic. Results Histochemical types of intestinal metaplasia showed as follows: Type I, 398 (77.7%); Type II, 81 (15.8%) and Type III, 33 (6.5%). The weighted Kappa statistic was 0.79 (p<0.001), rated as an important or good concordance. Conclusion This new algorithm demonstrated it was useful and capable of identifying and differentiating the histochemical types of intestinal metaplasia, in addition to having statistical reliability.

RESUMO Introdução A classificação da metaplasia intestinal por métodos histoquímicos tem sido descrita como a mais adequada. No entanto, os algoritmos atuais não são replicáveis?? em laboratórios devido a limitações severas. Objetivo Avaliar um novo algoritmo para diferenciar tipos histoquímicos de metaplasia intestinal. Material e Método: Pesquisa transversal em que 512 biópsias gástricas com metaplasia intestinal (blocos de parafina) foram avaliadas por um novo algoritmo usando dois tipos de corantes Alcian Blue durante fevereiro-março de 2020 no serviço de anatomia patológica do Hospital Maria Auxiliadora, Lima, Peru. Essa avaliação consistiu em duas etapas: visualização das mucinas ácidas nas células colunares da mucosa gástrica e cálculo da estatística Kappa ponderado. Resultados Os tipos histoquímicos de metaplasia intestinal mostraram-se a seguir: Tipo I, 398 (77,7%); Tipo II, 81 (15,8%) e Tipo III, 33 (6,5%). A estatística Kappa ponderado foi de 0,79 (p <0,001), classificada como concordância importante ou boa. Conclusão Este novo algoritmo demonstrou ser útil e capaz de identificar e diferenciar os tipos histoquímicos de metaplasia intestinal, além de possuir confiabilidade estatística

Caracterização dos fenótipos de mucina podem prever a recorrência do câncer gástrico precoce após a mucosectomia endoscópica / Characterization of the mucin phenotype can predict gastric cancer recurrence after endoscopic mucosal resection

ABSTRACT BACKGROUND: Endoscopic mucosal resection is still considered an accepted treatment for early gastric cancer for selected cases. Histopathologic criteria for curative endoscopic resection are intramucosal well-differentiated adenocarcinoma, lateral and deep margins free of tumor, no histological ulceration, and no venous or lymphatic embolism. A 5% local recurrence rate has been described even when all the above-mentioned criteria are met. On the other hand, antigen expression by tumoral cells has been related to the biological behavior of several tumors. OBJECTIVE: To evaluate whether early gastric cancer mucin immunoexpression, p53 and Ki-67, can predict recurrence after endoscopic mucosal resection, even when standard histopathologic criteria for curative measures have been attempted. METHODS: Twenty-two patients with early gastric cancer were considered to have been completely resected by endoscopic mucosal resection. Local recurrence occurred in 5/22 (22.7%). Immunohistochemical study was possible in 18 (81.8%) resected specimens. Patients were divided in two groups: those with and those without local recurrence. They were compared across demographic, endoscopic, histologic data, and immunohistochemical factors for MUC2, MUC5a, CD10, p53, and Ki-67. RESULTS: Mucin immunoexpression allowed a reclassification of gastric adenocarcinoma in intestinal (10), gastric (2), mixed (4), and null phenotypes (2). Mixed phenotype (positive for both MUC2 and MUC5a) was found in 80% of cases in the local recurrence group, while the intestinal type (positive MUC2 and negative MUC5a) was found in 76.9% of cases without local recurrence (P=0.004). Other observed features did not correlate with neoplastic recurrence. CONCLUSION: The mixed phenotype of early gastric adenocarcinoma is associated with a higher probability of local recurrence after endoscopic mucosal resection.

RESUMO CONTEXTO: A ressecção endoscópica da mucosa é tratamento aceito para o tratamento do câncer gástrico precoce em casos selecionados. Os critérios histopatológicos favoráveis à ressecção endoscópica curativa são adenocarcinomas intramucosos, bem diferenciados, com margens lateral e profunda livres, ausência de ulceração ou de embolização angiolinfática. Taxas de recorrência local próximas a 5% têm sido descritas mesmo quando se cumprem tais critérios. Por outro lado, a expressão antigênica por células tumorais tem sido relacionada com o comportamento biológico de diversos tumores. OBJETIVO: Avaliar se a imunoexpressão de mucinas, p53 e Ki-67 podem predizer a recorrência tumoral após mucosectomia endoscópica no câncer gástrico precoce, mesmo se critérios de cura histopatológicos forem atingidos. MÉTODOS: Vinte e dois pacientes com critérios de cura para ressecção endoscópica e sumetidos a mucosectomia foram selecionados. A recorrência local ocorreu em 5/22 (22,7%). O estudo imunohistoquímico foi realizado em 18 (81,8%) espécimens. Os pacientes foram divididos em grupos com e sem recorrência local. Foram comparados quanto a dados demográficos, endoscópicos, histológicos e fatores imunohistoquímicos para MUC2, MUC5A, CD10, p53, e Ki-67. RESULTADOS: A imunoexpressão de mucinas permitiu a reclassificação dos adenocarcinomas gástricos em intestinal (10), gástrico (2), e de fenótipo misto (4) e nulo (2). Os fenótipos mistos (positivos tanto para MUC2 quanto para MUC5A) foram encontrados em 80% dos casos no grupo de recorrência local, enquanto tipos intestinais (MUC2 positivo e MUC5A negativo) foram identificados em 76,9% dos casos sem recorrência (P=0,004). Os outros fatores observados não se relacionaram com a recorrência tumoral. CONCLUSÃO: O fenótipo misto do câncer gástrico precoce está associado a maior probabilidade de recorrência local após a mucosectomia.