Pathogenesis and management of serrated polyps: current status and future directions

Deficient mismatch repair screening of advanced adenomas in the population screening program for colorectal cancer is not effective

AIM

Currently, screening of colorectal cancers (CRC) by assessing mismatch repair deficiency (dMMR) or microsatellite instability (MSI) is used to identify Lynch syndrome (LS) patients. Advanced adenomas are considered immediate precursor lesions of CRC. In this study we investigate the relevance of screening of advanced adenomas for LS in population screening.

METHODS AND RESULTS

Advanced adenomas (n = 1572) were selected from the Dutch colorectal cancer population screening programme, based on one or more of the criteria: tubulovillous (n = 848, 54%) or villous adenoma (n = 118, 7.5%), diameter ≥ 1 cm (n = 1286, 82%) and/or high-grade dysplasia (n = 176, 11%). In 86 cases (5%), all three criteria were fulfilled at the same time. MMR-IHC and/or MSI analyses were performed on all cases. Only five advanced adenomas (0.3%) showed dMMR and MSI, including two cases with hypermethylation. In at least two patients a germline event was suspected based on allelic frequencies. No pathogenic explanation was found in the last case.

CONCLUSION

Timely testing of precursor lesions would be preferable to detect new LS patients before CRC development. However, standard assessment of dMMR of advanced adenomas from the population screening is not effective.

Association between endoscopist adenoma detection rate and serrated polyp detection: Retrospective analysis of over 200,000 screening colonoscopies

Background and study aims Serrated lesions have been identified as precursor lesions for 20% to 35% of colorectal cancers (CRCs) and may contribute to a significant proportion of interval-cancer. Sessile-serrated-lesions (SSLs), in particular, tend to be flat and located in the proximal colon, making their detection challenging and requiring expertise. It remains unclear whether the detection rate for serrated polyps should be considered as a quality indicator in addition to the adenoma detection rate (ADR). This study sought to assess whether the ADR has an effect on the detection rate for serrated polyps. atients and methods In this retrospective analysis, prospectively collected data from 212,668 screening colonoscopies performed between 2012 and September 2018 were included. Spearman correlation and Whitney-Mann U-test were used to assess the association of ADR and the detection rate of SSLs with (SDR) and without hyperplastic polyps (SPADRs), the sessile serrated detection rate (SSLDR) as well as the clinically relevant serrated detection rate (CRSDR), including all SSLs and traditional serrated adenoma, hyperplastic polyps (HPs) >10 mm anywhere in the colon or HPs > 5 mm proximal to the sigmoid. Results The overall mean ADR was 21.78% (standard deviation [SD] 9.27), SDR 21.08% (SD 11.44), SPADR 2.19% (SD 2.49), and CRSDR was 3.81% (3.40). Significant correlations were found between the ADR and the SDR, SPADR, SSLDR, and CRSDR (rho=0.73 vs. rho=0.51 vs. rho=0.51 vs. rho=0.63; all P <0.001). Endoscopists with a mean ADR ≥25% had significantly higher SDR, SPADR, and CRSDR than endoscopists with a mean ADR <25% (all P <0.001; Mann-Whitney U-Test). Conclusions This study shows that endoscopists with higher ADR detect significantly more serrated lesions than those with a lower ADR.

Serrated Polyp Yield at Colonoscopy in Patients with Positive FIT, Positive mt-sDNA, and Colonoscopy Only: Data from the New Hampshire Colonoscopy Registry

BACKGROUND

Stool-based screening with fecal immunochemical (FIT) or multitarget-stool DNA (mt-sDNA) tests is associated with increased colonoscopy polyp yield. mt-sDNA includes methylated markers, which improve detection of serrated polyps (SP) versus FIT. We compared SP detection in colonoscopies performed for positive FIT or mt-sDNA tests, as well as in colonoscopies without a preceding stool test, using the New Hampshire Colonoscopy Registry, a comprehensive statewide population-based registry.

METHODS

Across the three groups, we compared the frequency of clinically relevant SPs (CRSP: sessile SPs, hyperplastic polyps ≥10 mm, and traditional serrated adenomas). We also compared SP size, histology, number, and bulk (combined sizes).

RESULTS

Our sample included 560 mt-sDNA+ (age ± SD: 66.5 ± 7.9), 414 FIT+ (age ± SD: 66.3 ± 8.8), and 59,438 colonoscopy-only patients (age ± SD: 61.7 ± 8.0). mt-sDNA+ patients were more likely to have a higher yield of CRSPs and CRSP bulk than FIT+ (P < 0.0001) or colonoscopy-only patients (P < 0.0001). More mt-sDNA+ patients had CRSPs without large adenomas or colorectal cancers (17.9% vs. 9.9% of FIT+ and 8% of colonoscopy-only patients). After adjusting for synchronous large adenomas, colorectal cancers, and other risk factors, mt-sDNA+ patients were more likely (OR, 1.82; 95% CI, 1.18-2.85) than FIT+ patients to have CRSPs.

CONCLUSIONS

mt-sDNA+ patients had a higher SP yield than FIT+ or colonoscopy-only patients, particularly in the absence of synchronous large adenomas or colorectal cancer.

IMPACT

Our results suggest that screening with mt-sDNA tests could improve colorectal cancer screening by identifying more patients at increased risk from the serrated pathway.

Significance of the Entire Appendiceal Evaluation in the Diagnosis of Serrated Lesions, Low-Grade Appendiceal Mucinous Neoplasm, and Appendiceal Diverticulosis Disease

Objective

This study was conducted in order to investigate the significance of the entire appendiceal evaluation in the pathological diagnosis of appendiceal serrated lesions, low-grade appendiceal mucinous neoplasm (LAMN), and appendiceal diverticulosis disease (ADD).

Methods

A total of 702 appendectomy specimens diagnosed from 2017 to 2020 were reviewed retrospectively. The specimens were divided into two groups according to the different sampling procedures. In group 1, the vast majority of 337 specimens were partially submitted by routine sampling within 18 months from October 2017 to March 2019. In group 2, 365 of specimens were entirely submitted and examined within 18 months from April 2019 to October 2020. The incidence and pathological features of serrated lesions, LAMN, and ADD in the two groups were compared and analyzed. The clinicopathological characteristics between different entities were also studied.

Results

Forty appendiceal serrated lesions, 8 LAMNs, and 21 diverticula were accidentally detected in 702 appendectomy specimens. As compared with group 1, the incidence of appendiceal serrated lesions in group 2 was significantly increased (9.3% vs. 1.8%, P < 0.01), especially for the serrated lesions without dysplasia (7.4% vs. 1.2%, P < 0.01). The entire sampling revealed that loss of lamina propria and replacement with dysplastic mucinous epithelium were statistically significantly associated with LAMN rather than serrated lesions and ADD (P < 0.01 and P < 0.01, respectively). Mural mucin deposition and fibrosis were useful features to distinguish LAMN from simple serrated lesions (P < 0.01 and P < 0.05, respectively), but mucin deposition was useless for the distinction between LAMN and ADD (P > 0.05) or serrated lesions combined with ADD.

Conclusion

Our study highlights the importance and necessity of careful gross assessment and histologic examination of the entire appendectomy specimen, since the association with unexpected appendiceal lesions is significant and cannot be ignored. The entirely submitted appendix is more sensitive for the detection of appendiceal serrated lesions. In addition, thorough examination and evaluation are essential to distinguish the key pathological features between appendiceal serrated lesions, LAMN, and ADD.

Characteristics of Serrated Adenomas in Non-Hispanic Whites and African Americans Undergoing Screening Colonoscopy

Background and aim

Adenomatous polyps are precursor lesions for colorectal cancer (CRC). Serrated adenomas/polyps are considered a risk factor for the development of proximal and interval CRC. African-Americans are at higher risk for right-sided CRC. Minimal data evaluating serrated adenoma characteristics by race/ethnicity on initial screening colonoscopy (SC) exist. The aim of this investigation was to compare the characteristics of serrated adenomas found in non-Hispanic whites (nHw) and African-Americans (AA) undergoing initial SC.

Methods

The University of Florida-Jacksonville endoscopy database was searched for all SC performed between January 2000 and December 2014. Inclusion criteria were nHw or AA race/ethnicity and histologically proven serrated adenoma found at SC. Data were collected for all included age at SC, sex, number, location, and size of serrated adenomas found.

Results

A total of 8693 individuals (nHw - 4199 and AA - 4494) underwent SC between January 2000 and December 2014. Serrated adenomas were found in 479 individuals (nHw, n=294; AA, n=185), and AA were significantly less likely than nHw to have serrated adenomas on SC (AA 4.1% vs nHw 7%; p< 0.0001). No difference was observed in mean age, location, or size between nHw and AA with serrated adenomas.

Conclusions

Serrated adenomas are more frequent in nHw compared to AA at initial SC. No difference was seen in size or location of serrated adenomas, as well as patient age, between AA and nHw. A study of genetic factors predisposing to serrated adenoma formation and the impact of socioeconomic disparities should be performed across ethnic groups to understand this difference.

Diagnosis, epidemiology and management of serrated polyposis syndrome: a comprehensive review of the literature

Serrated polyp associated colorectal cancer (CRC) develops from an alternative mechanism of colorectal carcinogenesis and accounts for 10-15% of all CRC. Serrated polyposis syndrome (SPS) occurs infrequently and is characterized by the occurrence of multiple serrated polyps (hyperplastic polyps, sessile serrated lesions and traditional serrated adenomas) throughout the colon and/or rectum and has been strongly associated with development of CRC. However, SPS is frequently unrecognized, due to application failure of the WHO criteria regarding diagnosis and/or missed serrated polyps during endoscopy. The management of SPS requires surveillance at regular intervals and removal of large serrated polyps. Endoscopic resection suitability and technique depends on lesion size and the endoscopist's experience. In this manuscript, we present an update regarding SPS epidemiology, molecular characteristics, management, surveillance strategies and endoscopic resection techniques.

Clinical Features and Predictors of Dysplasia in Proximal Sessile Serrated Lesions

Background/Aims

Proximal colorectal cancers (CRCs) account for up to half of CRCs. Sessile serrated lesions (SSLs) are precursors to CRC. Proximal location and presence of dysplasia in SSLs predict higher risks of progression to cancer. The prevalence of dysplasia in proximal SSLs (pSSLs) and clinical characteristics of dysplastic pSSLs are not well studied.

Methods

Endoscopically resected colonic polyps at our center between January 2016 and December 2017 were screened for pSSLs. Data of patients with at least one pSSL were retrieved and clinicopathological features of pSSLs were analysed. pSSLs with and without dysplasia were compared for associations.

Results

Ninety pSSLs were identified, 45 of which had dysplasia giving a prevalence of 50.0%. Older age (65.9 years vs. 60.1 years, p=0.034) was associated with the presence of dysplasia. Twelve pSSLs were 10 mm or larger. After adjusting for age, pSSLs ≥10 mm had an adjusted odds ratio of 5.98 (95% confidence interval, 1.21–29.6) of having dysplasia compared with smaller pSSLs.

Conclusions

In our cohort of pSSLs, the prevalence of dysplasia is high at 50.0% and is associated with lesion size ≥10 mm. Endoscopic resection for all proximal serrated lesions should be en bloc to facilitate accurate histopathological examination for dysplasia as its presence warrants shorter surveillance intervals.

Epigenetics of colorectal cancer: biomarker and therapeutic potential

Colorectal cancer (CRC), a leading cause of cancer-related death worldwide, evolves as a result of the stepwise accumulation of a series of genetic and epigenetic alterations in the normal colonic epithelium, leading to the development of colorectal adenomas and invasive adenocarcinomas. Although genetic alterations have a major role in a subset of CRCs, the pathophysiological contribution of epigenetic aberrations in this malignancy has attracted considerable attention. Data from the past couple of decades has unequivocally illustrated that epigenetic marks are important molecular hallmarks of cancer, as they occur very early in disease pathogenesis, involve virtually all key cancer-associated pathways and, most importantly, can be exploited as clinically relevant disease biomarkers for diagnosis, prognostication and prediction of treatment response. In this Review, we summarize the current knowledge on the best-studied epigenetic modifications in CRC, including DNA methylation and histone modifications, as well as the role of non-coding RNAs as epigenetic regulators. We focus on the emerging potential for the bench-to-bedside translation of some of these epigenetic alterations into clinical practice and discuss the burgeoning evidence supporting the potential of emerging epigenetic therapies in CRC as we usher in the era of precision medicine.

A Role for the WNT Co-Receptor LRP6 in Pathogenesis and Therapy of Epithelial Cancers

The WNT/β-catenin signaling pathway controls stem and progenitor cell proliferation, survival and differentiation in epithelial tissues. Aberrant stimulation of this pathway is therefore frequently observed in cancers from epithelial origin. For instance, colorectal and hepatic cancers display activating mutations in the CTNNB1 gene encoding β-catenin, or inactivating APC and AXIN gene mutations. However, these mutations are uncommon in breast and pancreatic cancers despite nuclear β-catenin localization, indicative of pathway activation. Notably, the low-density lipoprotein receptor-related protein 6 (LRP6), an indispensable co-receptor for WNT, is frequently overexpressed in colorectal, liver, breast and pancreatic adenocarcinomas in association with increased WNT/β -catenin signaling. Moreover, LRP6 is hyperphosphorylated in KRAS-mutated cells and in patient-derived colorectal tumours. Polymorphisms in the LRP6 gene are also associated with different susceptibility to developing specific types of lung, bladder and colorectal cancers. Additionally, recent observations suggest that LRP6 dysfunction may be involved in carcinogenesis. Indeed, reducing LRP6 expression and/or activity inhibits cancer cell proliferation and delays tumour growth in vivo. This review summarizes current knowledge regarding the biological function and regulation of LRP6 in the development of epithelial cancers—especially colorectal, liver, breast and pancreatic cancers.

Smoking and Other Risk Factors in Individuals With Synchronous Conventional High-Risk Adenomas and Clinically Significant Serrated Polyps

BACKGROUND AND AIMS

Serrated polyps (SPs) and conventional high-risk adenomas (HRAs) derive from two distinct biological pathways but can also occur synchronously. Adults with synchronous SPs and adenomas have been shown to be a high-risk group and may have a unique risk factor profile that differs from adults with conventional HRAs alone. We used the population-based New Hampshire Colonoscopy Registry (NHCR) to examine the risk profile of individuals with synchronous conventional HRAs and SPs.

METHODS

Our study population included 20,281 first time screening colonoscopies from asymptomatic NHCR participants 40 years or older between 2004-15. Exams were categorized by findings: (1) normal, (2) HRA only (adenomas ≥ 1 cm, villous, high grade dysplasia, multiple adenomas ( > 2) and adenocarcinoma), (3) clinically significant SP (CSSP) only (any hyperplastic polyp ≥ 1 cm, sessile serrated adenomas/polyps or traditional serrated adenomas), and (4) synchronous HRA + CSSP. Risk factors examined included exposure of interest, smoking (never, past, and current/pack years), as well as age, sex, alcohol, education, and family history of colorectal cancer (CRC). Multivariable unconditional logistic regression tested the relation of risk factors with having synchronous HRA + CSSP versus having a normal exam or HRA alone.

RESULTS

Among NHCR participants with 18,354 screening colonoscopies (with complete smoking, sex, bowel preparation data, and adequate preparation) there were 16,495 normal; 1309 HRA alone; 461 CSSP alone, and 89 synchronous HRA + CSSP. Current smoking was associated with an almost threefold increased risk for HRA or CSSP, and an eightfold risk for synchronous HRA + CSSP (aOR = 8.66; 95% CI: 4.73-15.86) compared to normal exams. Adults with synchronous HRA + CSSP were threefold more likely to be current smokers than those with HRA alone (aOR = 3.27; 95% CI:1.74-6.16).

CONCLUSIONS

Our data suggest that current smokers may be at a higher risk for synchronous CSSP + HRA even when compared to having HRA alone.

KRAS and BRAF somatic mutations in colonic polyps and the risk of metachronous neoplasia

Background & aims

High-risk features of colonic polyps are based on size, number, and pathologic characteristics. Surveillance colonoscopy is often recommended according to these findings. This study aimed to determine whether the molecular characteristics of polyps might provide information about the risk of metachronous advanced neoplasia.

Methodology

We retrospectively included 308 patients with colonic polyps. A total of 995 polyps were collected and tested for somatic BRAF and KRAS mutations. Patients were classified into 3 subgroups, based on the polyp mutational profile at baseline, as follows: non-mutated polyps (Wild-type), at least one BRAF-mutated polyp, or at least one KRAS-mutated polyp. At surveillance, advanced adenomas were defined as adenomas ≥ 10 mm and/or with high grade dysplasia or a villous component. In contrast, advanced serrated polyps were defined as serrated polyps ≥ 10 mm in any location, located proximal to the splenic flexure with any size or with dysplasia.

Results

At baseline, 289 patients could be classified as wild-type (62.3%), BRAF mutated (14.9%), or KRAS mutated (22.8%). In the univariate analysis, KRAS mutations were associated with the development of metachronous advanced polyps (OR: 2.36, 95% CI: 1.22–4.58; P = 0.011), and specifically, advanced adenomas (OR: 2.42, 95% CI: 1.13–5.21; P = 0.023). The multivariate analysis, adjusted for age and sex, also showed associations with the development of metachronous advanced polyps (OR: 2.27, 95% CI: 1.15–4.46) and advanced adenomas (OR: 2.23, 95% CI: 1.02–4.85).

Conclusions

Our results suggested that somatic KRAS mutations in polyps represent a potential molecular marker for the risk of developing advanced neoplasia.

Hereditary Colorectal Cancer Syndromes

Awareness of hereditary colorectal cancer syndromes is important to facilitate their identification because affected patients are at increased risk for early onset, synchronous, and metachronous colorectal malignancies, and certain extracolonic malignancies depending on the syndrome. Identification of an affected individual allows for screening and early interventions for patients and their at-risk kindred. Genetic counseling and testing is important to the care of these patients. As knowledge of the genetic basis of these syndromes grows, unique genotype-phenotype profiles allow clinicians to tailor surveillance and treatment strategies based on individual risk.

Detection Rate, Distribution, Clinical and Pathological Features of Colorectal Serrated Polyps

Background:

Colorectal serrated polyp is considered as histologically heterogeneous lesions with malignant potential in western countries. However, few Asian studies have investigated the comprehensive clinical features of serrated polyps in symptomatic populations. The aim of the study was to evaluate the features of colorectal serrated polyps in a Chinese symptomatic population.

Methods:

Data from all consecutive symptomatic patients were documented from a large colonoscopy database and were analyzed. Chi-square test or Fisher's exact test and logistic regression analysis were used for the data processing.

Results:

A total of 9191 (31.7%) patients were detected with at least one colorectal polyp. The prevalence of serrated polyps was 0.53% (153/28,981). The proportions of hyperplastic polyp (HP), sessile serrated adenoma/polyp (SSA/P), and traditional serrated adenoma (TSA) of all serrated polyps were 41.2%, 7.2%, and 51.6%, respectively, which showed a lower proportion of HP and SSA/P and a higher proportion of TSA. Serrated polyps appeared more in males and elder patients while there was no significant difference in the subtype distribution in gender and age. The proportions of large and proximal serrated polyps were 13.7% (21/153) and 46.4% (71/153), respectively. In total, 98.9% (89/90) serrated adenomas were found with dysplasia. Moreover, 14 patients with serrated polyps were found with synchronous advanced colorectal neoplasia, and large serrated polyps (LSPs) (odds ratio: 3.446, 95% confidence interval: 1.010–11.750, P < 0.05), especially large HPs, might have an association with synchronous advanced neoplasia (AN).

Conclusions:

The overall detection rate of colorectal serrated polyps in Chinese symptomatic patient population was low, and distribution pattern of three subtypes is different from previous reports. Moreover, LSPs, especially large HPs, might be associated with an increased risk of synchronous AN.

Clinicopathological characteristics of serrated polyps as precursors to colorectal cancer: Current status and management

Serrated polyps have long been thought to lack malignant potential in the human colorectum. However, identification of the serrated pathway to colorectal cancer based on molecular biology has improved our understanding of the pathogenesis of colorectal cancers. Accordingly, serrated polyps such as traditional serrated adenoma and sessile serrated adenoma/polyps (SSA/P) are now considered to be precursor lesions of the serrated pathway. Recently, serrated polyps were classified into three subtypes, consisting of hyperplastic polyp, SSA/P, and traditional serrated adenoma, according to the World Health Organization classification. It has been suggested that SSA/P in the proximal colon are a precursor lesion of pathogenesis of colorectal cancer and are characterized by BRAF mutation and a CpG island methylator phenotype with or without microsatellite instability. However, SSA/P is more challenging to detect by colonoscopy and is likely to account for some interval cancers, particularly in the proximal colon because it presents flat or sessile, isochroous appearance, and occasionally has a mucous cap. Furthermore, the possibility has been raised that pathologists misclassify SSA/P as hyperplastic polyp. It is important for gastroenterologists to recognize the endoscopic features of serrated polyps to facilitate their detection and removal and also to establish postpolypectomy surveillance guidelines. In this review, we discuss the recent classification of serrated polyps; the molecular characteristics of the serrated pathway; appropriate diagnostic methods using endoscopy, including a new image-enhanced endoscopic technique; and management of these lesions.

Adenoma Detection Rates for Screening Colonoscopies in Smokers and Obese Adults: Data From the New Hampshire Colonoscopy Registry

GOAL

To examine screening adenoma detection rates (ADR) and serrated detection rates (SDR) among smokers and obese adults in the New Hampshire Colonoscopy Registry.

BACKGROUND

ADR, a quality measure for screening colonoscopies, is associated with protection from interval colorectal cancer. Currently, only sex-specific ADR benchmarks are reported. However, obesity and smoking ≥20 pack-years are strong predictors for colorectal neoplasia, as highlighted by the 2009 American College of Gastroenterology CRC Screening Guidelines. Data comparing ADR in smokers and obese adults to those without these risks are limited.

STUDY

We calculated ADR, SDR, and 95% confidence intervals for screening colonoscopies in participants ≥50 years. Sex-specific and sex-age-specific rates were compared by smoking exposure (never vs. <20 vs. ≥20 pack-years) and body mass index (<30 vs. ≥30).

RESULTS

A total of 21,539 screening colonoscopies were performed by 77 endoscopists at 20 facilities (April 2009 to September 2013). The difference in ADR between nonsmokers and smokers with ≥20 pack-years was 8.8% (P<0.0001) and between obesity groups 5.0% (P<0.0001). Significant sex-specific and sex-age-specific increases in ADR and SDR were found among smokers and obese participants.

CONCLUSIONS

ADR and SDR for smokers and obese adults were significantly higher than their counterparts without those risks. Endoscopists should consider the prevalence of these risks within their screening population when comparing their rates to established benchmarks. Calculating sex-specific or sex-age-specific ADR and SDR based on smoking and obesity may provide optimal protection for populations with a particularly high prevalence of smokers and obese adults.

Clinical features of upper gastrointestinal serrated lesions: An endoscopy database analysis of 98746 patients

AIM

To analyse the clinical features of patients with the serrated lesions in the upper gastrointestinal tract (UPGI) tract.

METHODS

Patients who underwent routine esophagogastroduodenoscopy (EGD) at the Digestive Endoscopy Centre of General Hospital, Tianjin Medical University between January 2011 and December 2015 were consecutively recruited. Patients with UPGI serrated lesions were consecutively identified. The patients’ demographics and histopathology were recorded. The colorectal findings for patients who underwent colonoscopy simultaneously or within six months were also extracted from the colonoscopy database. In addition, we analysed differences in colorectal neoplasia detection between the study patients and randomly selected patients matched for age and gender who did not exhibit serrated lesions and who also underwent colonoscopy in the same period.

RESULTS

A total of 21 patients out of 98746 patients (0.02%) who underwent EGD were confirmed to have serrated lesions with predominantly crenated, sawtooth-like configurations. The mean age of the 21 patients was (55.3 ± 17.2) years, and 11 patients were male (52.4%). In terms of the locations of the serrated lesions, 17 were found in the stomach (including 3 in the cardia, 9 in the corpus and 5 in the antrum), 3 were found in the duodenum, and 1 was found in the esophagus. Serrated lesions were found in different mucosal lesions, with 14 lesions were detected in polyps (8 hyperplastic polyps and 6 serrated adenomas with low grade dysplasia), 3 detected in Ménétrier gastropathy, 3 detected in an area of inflammation or ulcer, and 1 detected in the intramucosal carcinoma of the duodenum. In addition, colonoscopy data were available for 18 patients, and a significantly higher colorectal adenoma detection rate was observed in the UPGI serrated lesions group than in the randomly selected age- and gender-matched group without serrated lesions who also underwent colonoscopy in the same period (38.9% vs 11.1%, OR = 5.091, 95%CI: 1.534-16.890, P = 0.010). The detection rate of advanced adenoma was also higher in the UPGI serrated lesions group (22.2% vs 4.2%, OR = 6.571, 95%CI: 1.322-32.660, P = 0.028).

CONCLUSION

Serrated lesions in the UPGI were detected in various mucosal lesions with different pathological morphologies. Moreover colonoscopy is recommended for the detection of concurrent colorectal adenoma for these patients.

Comparative analysis of endoscopic and histopathological features of superficial elevated lesions resected by endoscopic mucosal resection in the distal and proximal colon

OBJECTIVE

to compare endoscopic and histopathologic features of superficial, elevated lesions with one or more centimeters in diameter, diagnosed by videocolonoscopy on the distal and proximal colon, and subjected to mucosal resection.

METHODS

we conducted a retrospective, cross-sectional, observational study involving 8,075 videocolonoscopies. From this total, we evaluated 166 mucosectomies in 145 patients with superficial, elevated lesions with a diameter equal to or greater than 1cm.

RESULTS

the lesion prevalence was lower in G1 than in G2 (34.9% vs. 65%). The mean age, gender distribution and size (1.9cm in G1 versus 2.0cm in G2, p=0.921) were similar. There was no difference of mucosal surfaces in relation to the location (p=0.575). Considering Intraepithelial neoplasias, both the low grade, high grade (including carcinomas) and hyperplasic ones showedd no difference (p=0.527), nor did the neoplastic lesions when divided into serrated and non-serrated (p=0.124). Excluding 13 hyperplastic lesions and two carcinomas, 124 (82.1%) were non-serrated and 27 (17.9%), serrated.

CONCLUSION

were found no significant differences between endoscopic and histopathological aspects of superficial, elevated lesions of 1cm or more in diameter in distal colon compared with the proximal, when resected by mucosectomy. Although not significant, there was a tendency of association between the location of the lesion and the presence of serrated features.

OBJETIVO

comparar aspectos endoscópicos e histopatológicos de lesões superficialmente elevadas, com um ou mais centímetros de diâmetro, diagnosticadas por videocolonoscopias e ressecadas por mucosectomias do cólon distal com as do cólon proximal.

MÉTODOS

estudo foi retrospectivo, transversal, observacional, envolvendo 8075 videocolonoscopias. Avaliou-se 166 mucosectomias em 145 pacientes com lesões superficialmente elevadas com diâmetro igual ou maior do que 1cm.

RESULTADOS

a prevalência de lesões foi menor no G1 do que no G2 (34,9% x 65%). A média de idade, a distribuição por sexo e o tamanho (1,9cm no G1 e 2cm no G2, p=0,921) foram semelhantes. Não houve diferenças das superfícies em relação à localização (p=0,575). Considerando neoplasia intraepitelial de baixo grau, neoplasia intraepitelial de alto grau (incluindo carcinomas) e hiperplásicas, não houve diferença (p=0,527), assim como quando foram divididas as lesões neoplásicas em serrilhadas e não serrilhadas (p=0,124). Excluindo-se 13 lesões hiperplásicas e duas com carcinomas, 124 (82,1%) foram não serrilhadas e 27 (17,9%) serrilhadas.

CONCLUSÃO

não foram observadas diferenças significativas entre os aspectos endoscópicos e os histopatológicos das lesões superficialmente elevadas, com 1cm ou mais de diâmetro, ressecadas por mucosectomia do cólon distal em relação ao proximal. Embora não significante, há tendência à associação entre a localização da lesão e a presença de características serrilhadas.

Intramucosal carcinoma of the appendix arising from traditional serrated adenoma

Introduction. Serrated adenomas of the appendix are rare and usually found during appendectomy or autopsies. The preoperative diagnosis of these tumors is uncommon. This report describes a case of a sessile serrated adenoma located in the appendix diagnosed by a screening colonoscopy and successfully treated by laparoscopic removal. Presentation of Case. An 86-year-old woman underwent colonoscopy to investigate the cause of her diarrhea, weight loss, and anemia. During the colonoscopy, an expansive and vegetating mass of 1.5 cm in diameter was identified, protruding through the appendicular ostium with slightly lateral growth to the cecum. The patient was referred for laparoscopic surgical resection due to the location of the lesion, which did not allow its removal by colonoscopy. She underwent wedge removal of the cecum without complications and was discharged on the 4th postoperative day. Histopathological examination showed the presence of a sessile serrated adenoma with an intramucosal adenocarcinoma. The patient is currently well one year after surgery, without endoscopic signs of relapse. Conclusion. Despite serrated adenomas being a possibility rarely described in appendix it should be recognized and properly treated because it is presenting a higher risk of cancer.