Search Results (232)

Colorectal cancer, as a malignant tumor with a high incidence rate worldwide, relies on the precise segmentation of polyps during colonoscopy for its early diagnosis. However, clinical colonoscopy images often face challenges such as low contrast, blurred boundaries, large differences in morphological scale, and interference from intestinal wall folds, resulting in insufficient accuracy of traditional segmentation methods. To address the above problems, this paper proposes a PCA-TransUNet model based on the parallel cross-attention mechanism, taking TransUNet as the baseline framework and introducing the parallel cross-attention module in its skip connections. This module consists of two branches: channel cross-attention and spatial cross-attention. The channel branch enhances the semantic feature discrimination through cross-scale channel interaction, while the spatial branch optimizes the boundary positioning accuracy by using long-range dependency relationships. The outputs of the two are adaptively integrated through a dynamic weighted fusion mechanism to form multi-scale enhanced features, significantly improving the segmentation robustness in complex scenarios. Experiments on the CVC-ClinicDB and Kvasir-SEG datasets show that the model proposed in this paper outperforms the comparison models in multiple indicators. PCA-TransUNet achieved mIoU of 92.89% and Dice of 95.79% on CVC-ClinicDB, and 90.81% and 95.25%, respectively, on Kvasir-SEG, providing reliable technical support for clinical auxiliary diagnosis. Full article

Foreign material is an uncommon finding in routine gastrointestinal histopathology, but may occasionally contribute to disease pathogenesis or create diagnostic pitfalls. We report two illustrative cases highlighting the diverse clinical and histologic implications of ingested plant material. The first case involves a 10-year-old boy who presented with clinical features consistent with acute appendicitis and underwent appendectomy. Although gross examination revealed a macroscopically unremarkable appendix, histological evaluation demonstrated mucosal ulceration associated with an impacted plant seed within the appendiceal lumen, supporting a diagnosis of obstructive acute appendicitis. The second case describes a 60-year-old woman undergoing a screening colonoscopy, during which a small sessile lesion in the transverse colon was resected. Histologic examination revealed no colonic mucosa; instead, the specimen consisted entirely of plant material, morphologically consistent with a tomato seed, representing an incidental finding mimicking a colonic polyp. These cases underscore that plant seeds, while rare, may act as obstructive agents in appendicitis or simulate true pathological lesions during endoscopic and histologic evaluation. Awareness of the characteristic microscopic features of plant material is essential to avoid misdiagnosis and to recognise their potential clinical and forensic relevance. Full article

Background/Objectives: Liquid profiling of molecular and epigenetic markers in bodily fluids is an expanding field of cancer biomarker research. Recent research activity also reveals the human satellite 2 (HSAT2) repetitive element cell-free DNA (cfDNA) as a potential cancer biomarker. Based on our recent results from targeted sequencing of HSAT2 cfDNA, we tested whether a specific HSAT2 sequence (e.g., 95 bp-HSAT2) shows greater cancer enrichment than 114 bp-SAT2, from which it derives, in patients with colon cancer. Methods: By comparing the ratio of 114 bp-HSAT2 to 95 bp-HSAT2, we investigated the increased cancer enrichment of 95 bp-HSAT2 in cfDNA samples obtained from plasma DNA extraction and a hybridization capture assay, in which HSAT2 sequences were captured from plasma using a biotin-labeled probe, in samples from colon cancer patients (n = 60) and polyp-controls (n = 60), and polyp-free controls (n = 60). Results: A correlation analysis between Ct values from DNA extraction and the hybridization capture assay for both 95 bp- and 114 bp-HSAT2 showed a positive correlation in patients with colon cancer and control subjects, indicating that the hybridization capture assay provides HSAT2 levels comparable to those obtained by DNA extraction. With both approaches, we found a lower 114 bp-HSAT2 to 95 bp-HSAT2 ratio in patients with colon cancer than in the control groups. The median ratio of extracted DNA was 62, 78, and 79 in patients with colon cancer, polyp-controls (p = 0.23), and polyp-free controls (p = 0.067), respectively. Capture assay values were 49, 87, and 64 in patients with colon cancer, polyp controls (p = 0.016), and polyp-free controls (p = 0.19), respectively. Even though statistical significance was not achieved in some comparisons, these results suggest that 95 bp-HSAT2 is more abundant in the blood of patients with colon cancer than 114 bp-HSAT2 in non-malignant patients. Conclusions: To our knowledge, this is the first study to conduct a hybridization capture assay using a biotinylated probe as a feasible approach for targeted enrichment of cfDNA from plasma. Our results confirm the outcomes of our recent article based on targeted sequencing and reveal that some specific HSAT2 sequences may exhibit increased cancer abundance. Full article

Background/Objectives: Ampullary adenomas are neoplasms of the gastrointestinal tract with malignant potential. They are thought to develop through pathways similar to those involved in colorectal neoplasia. This study aimed to determine the prevalence of colonic polyps in patients with ampullary adenoma. Methods: This retrospective study included a total of 35 patients with ampullary adenoma diagnosed between 2023 and 2024 and 105 sex-matched controls. Colonoscopic findings of the patient and control groups were compared with respect to polyp prevalence. In addition, the effects of dysplasia grade of the ampullary adenoma and patient age on polyp prevalence were evaluated. Results: The study included 35 patients (57% male) and 105 controls (59% male). The mean age was 67.06 ± 13.32 years in patients and 61.28 ± 8.42 years in controls. Colonic polyps were detected in 13 (57%) patients in the low-grade dysplasia (LGD) group, 6 (66%) patients in the high grade dysplasia (HGD) or adenocarcinoma group, and 54 (51%) patients in the control group (p = 0.02). After adjusting for age, colonic polyps remained significantly more frequent in the adenoma group than in controls (p = 0.05). Polyp prevalence was not associated with dysplasia grade on ampullary biopsy, and no significant differences were observed between groups regarding polyp histopathology, location, or size. Conclusions: In conclusion, our study indicates that colorectal polyp prevalence is increased among patients with ampullary adenomas and that this association may be independent of age as well as dysplasia severity. Therefore, colonoscopic evaluation may be recommended for all patients diagnosed with ampullary adenoma. Full article

Background/Objectives: Large (≥20 mm) non-pedunculated colorectal polyps (LNPCPs) are challenging lesions with a variable, yet non-negligible risk of advanced neoplasia. While correct management is therefore mandatory, a discrepancy often persists between guideline recommendations and daily endoscopic practice. To bridge this gap, we performed a comprehensive and structured review of the available evidence, aiming to synthesize the current knowledge and provide practice-oriented guidance for the optimal management of LNPCPs throughout the diagnostic–therapeutic pathway. Methods: A comprehensive literature review was independently performed. We systematically searched PubMed and Google Scholar up to December 2025. After the literature review, we identified the most clinically relevant and controversial aspects in the endoscopic management of LNPCPs. These key areas were then translated into focused, practice-oriented clinical questions. Results: We formulated 14 practice-oriented questions addressing the key steps of endoscopic management of LNPCPs. These questions cover the entire diagnostic–therapeutic pathway, including lesion detection, morphological characterization, optical diagnosis and risk stratification for submucosal invasion, selection of the optimal resection technique, and post-resection surveillance strategies. For each question, the current evidence was synthesized to provide concise, clinically applicable answers aimed at supporting real-world endoscopic decision-making. Conclusions: The endoscopic management of LNPCPs requires a structured and evidence-based approach that integrates accurate assessment, appropriate technique selection, and tailored post-resection surveillance. By framing current evidence into focused, practice-oriented questions, this review aims to bridge the gap between guideline recommendations and real-world endoscopic practice. The proposed framework may support endoscopists in daily clinical decision-making, promoting the appropriate use of advanced endoscopic techniques and ultimately improving patient outcomes. Full article

Background and Clinical significance: Cowden syndrome is an autosomal dominant disorder caused by germline loss-of-function mutations in the PTEN tumor suppressor gene. It is characterized by multiple hamartomas and an increased lifetime risk of malignancies affecting the breast, thyroid, endometrium, and gastrointestinal (GI) tract. Pediatric presentations may include macrocephaly, scrotal tongue, and intellectual disability. Gastrointestinal involvement is frequent, with juvenile-like hamartomatous polyps occurring in at least half of patients and distributed throughout the GI tract, posing a risk for malignant transformation. Early diagnosis and surveillance are crucial for improving patient outcomes. Case Presentation: We report a case of a 10-year-old Caucasian female with Cowden syndrome, with a history of a malignant germ cell tumor of the ovary consisting of a yolk sac tumor and low-grade immature teratoma diagnosed at age six, and thyroidectomy at age nine. The patient has mild intellectual disability. Routine radiological surveillance revealed a right colon intraluminal mass, prompting referral for pediatric gastroenterology evaluation. Endoscopy identified multiple polyps throughout the colon, stomach, and small intestine. Polypectomy of larger lesions was performed, and histopathology confirmed juvenile-like hamartomatous polyps without dysplasia or malignancy. This case highlights the necessity of comprehensive gastrointestinal evaluation in pediatric Cowden syndrome patients. Endoscopic surveillance is essential for early detection and management of polyps. Conclusions: Given the multisystem involvement and elevated cancer risk associated with PTEN mutations, a multidisciplinary approach that includes genetic counseling, dermatologic evaluation, and ongoing oncologic monitoring is recommended. Increased awareness of gastrointestinal manifestations enables timely intervention and may reduce morbidity and mortality in this high-risk population. Full article

Background/Objectives: It is recommended that patients with cirrhosis receive endoscopic screening for esophageal varices because of portal hypertension. However, patients with primary biliary cholangitis (PBC) do not routinely undergo endoscopic examinations. Nevertheless, although bile acids may increase the incidence rate of colon polyps by inducing colonic epithelium cell damage, only a few studies have discussed colonic findings in PBC patients, which are believed to be related to cholestasis. The issues regarding PBC patients’ endoscopic characteristics are still unclear. Methods: This retrospective study was conducted at the Tri-Service General Hospital, Taiwan, and comprised data from patients aged >20 years diagnosed with primary biliary cholangitis between January 2000 and December 2018 after approval from the institutional review board. In these PBC patients, endoscopic findings were recorded, including esophagogastroduodenoscopy (EGD) and colonoscopy. Conclusions: In the PBC group, only 28 patients received EGD examinations. Among the 28 PBC patients who underwent EGD, 13 (46.4%) had EV, and there were no varices in the control group (p < 0.05). Patients with PBC also presented a higher incidence rate of colon polyps (50% vs. 14%; p < 0.001). The findings regarding the higher risks of esophageal varices and colon polyps support the rationale for endoscopic examination in PBC patients. Full article

Background: Less than 1% of all colorectal cancers (CRCs) are primary colorectal signet-ring cell carcinomas (SRCCs), which represent an uncommon and aggressive histological subtype. Given their subtle onset and rapid progression, these are often diagnosed in an advanced stage, and can be distinguished by the presence of mucin-producing signet-ring cells. Synchronous colonic metastases at initial diagnosis are rather uncommon. Case presentation: We report the case of a 65-year-old male patient who underwent a routine colonoscopy following a positive fecal immunochemical test (FIT). The patient had no remarkable medical history and was asymptomatic. A 3 cm semi-pedunculated polyp and several smaller depressed lesions, 2 cm maximum in diameter, were observed in the descending colon during the colonoscopy. Multiple biopsies were obtained. The lesions were found to be SRCC according to histopathological examination. There was no sign of extra-colonic metastases on the computed tomography (CT). The patient was referred for extensive hemicolectomy, regional lymphadenectomy, and adjuvant chemotherapy. Conclusions: This article provides a thorough literature review on this uncommon presentation and discussion regarding the current understanding of the pathogenesis, clinical manifestations, and management strategies of SRCC. This case highlights the importance of routine screening in detecting aggressive malignancies like SRCC in asymptomatic individuals. Early identification through colonoscopy can lead to timely intervention, potentially improving prognosis. Full article

This paper proposes a Dual-path Feature-enhanced Fusion Network (DPF-Net) for medical image segmentation to address limitations in existing methods, including insufficient edge feature extraction, semantic gaps among multi-scale encoder features, and significant semantic disparities between the encoder and decoder in U-Net architectures. To this end, we design a symmetric encoder–decoder structure based on U-Net and introduce three core modules: the Edge Feature Gating (EFG) module, which extracts and integrates edge features from shallow encoder layers to enhance edge integrity; the Cross-channel Fusion Transformer (CCFT) module, embedded in skip connections, to achieve comprehensive and semantically balanced multi-scale cross-fused features; and the Dual-path Feature Fusion (DPFM) module, which combines channel and spatial attention mechanisms to effectively bridge the semantic gap between encoder and decoder features while improving spatial resolution recovery accuracy. Experimental results demonstrate that DPF-Net achieves superior performance on six public datasets covering gland segmentation, colon polyp segmentation, and skin lesion segmentation tasks, significantly outperforming existing methods in terms of both mDice and IoU metrics. The conclusions confirm that the proposed method not only comprehensively improves the overall accuracy and edge segmentation quality of medical image segmentation but also enhances the model’s generalization capability across different tasks. Full article

Background and Aims: Colon capsule endoscopy (CCE) provides a non-invasive alternative to traditional colonoscopy. This study evaluated the feasibility, safety, diagnostic yield (DY), and patient satisfaction of the OMOM CC100 CCE system, with special focus on fully remote (n = 30) and partially remote (n = 89) administration across four centres to advance decentralised models. Methods: This prospective, investigator-initiated, international multicentre feasibility study enrolled 119 patients aged 18–75 years at centres in Denmark, Sweden, Portugal, and Poland from July 2024 to May 2025. Indications included rectal bleeding, iron-deficiency anaemia, a positive faecal immunochemical test, changes in bowel habit, suspected inflammatory bowel disease (IBD), post-polypectomy or colorectal cancer (CRC) surgery surveillance, and a family history of CRC. The OMOM CC100 capsule was employed with a standardised bowel preparation regimen. Administration was fully remote in Denmark using the IntelliGI™ platform and partially remote (clinic ingestion, home completion) at the other sites. Primary outcomes encompassed procedure feasibility, completion rate (capsule excretion or anal verge visualisation), bowel cleanliness (Leighton-Rex scale ≥ 3), diagnostic yield, and patient satisfaction. Secondary measures included transit times, adverse events, and technical failures. Results: Median age was 55.7 years (65 males, 54 females). Overall completion rate was 79%, varying by centre: Sweden (90%), Portugal (81%), Denmark (80%), and Poland (63%). Adequate bowel cleanliness was achieved in 71% of cases. Diagnostic findings included polyps (25 patients), angioectasia (20), diverticulosis (17), and mucosal inflammation (17); 42% were normal. Fully remote administration yielded 80% completion and 89.7% satisfaction. No serious adverse events occurred; overall satisfaction was 81%, with 87% preferring home-based procedures. Conclusions: The OMOM CC100 CCE system is feasible, safe, with DY comparable to established systems. IntelliGI™-enabled remote administration promotes decentralised care, enhancing accessibility. Full article

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality worldwide, underscoring the urgent need for reliable biomarkers and therapeutic targets. To address this need, we focused on UDP-glucose pyrophosphorylase 2 (UGP2). Although UGP2 has been implicated in tumorigenesis across multiple cancers, its precise role and clinical significance in CRC remain poorly understood. This study aimed to comprehensively characterize UGP2 in CRC through an integrated approach encompassing proteomic screening, bioinformatics analysis, and experimental validation. We identified UGP2 as a significantly downregulated tumor-suppressive factor in CRC. Specifically, UGP2 expression was significantly downregulated in CRC tissues compared with that in normal controls and exhibited strong correlations with aggressive clinicopathological features, including lymphatic invasion, perineural invasion, and colon polyp history, and patient age. It also demonstrated high diagnostic accuracy in CRC, with an area under the receiver operating characteristic curve (AUC) of 0.990. Reduced UGP2 levels were associated with poorer overall survival and disease-specific survival. Hypermethylation of the UGP2 promoter correlated with a favorable prognosis in patients with CRC. UGP2 expression positively correlated with immune cell infiltration within the tumor microenvironment. Functionally, UGP2 knockdown increased CRC cell proliferation and migration while suppressing apoptosis. Conversely, its overexpression yielded the opposite effects, confirming UGP2’s role in constraining malignant phenotypes. Collectively, these findings establish UGP2 as a key CRC tumor suppressor whose downregulation drives malignant progression and predicts adverse clinical outcomes, suggesting its potential as a dual-purpose diagnostic and prognostic biomarker. Full article

Background: Colorectal cancer (CRC) is a leading cause of cancer death, and the incidence and mortality rates among young adults are rising. Although a subset of CRC cases presents with a family history, suggesting a hereditary component, the specific genetic underpinnings remain incompletely understood, particularly in early-onset CRC (EOCRC). This study aimed to discover novel risk genes for EOCRC using exome sequencing and gene-based rare variant burden testing. Methods: Our cohort consisted of 212 European-ancestry cases (174 diagnosed with CRC and 38 with significant polyps) from the South Australian Young Onset Colorectal Polyp and Cancer Study (SAYO) and 31,699 unaffected controls from the Simons Foundation Powering Autism Research for Knowledge (SPARK) cohort. After filtering for ancestry, relatedness, variant quality, and population allele frequency, we performed gene-set and individual-gene burden tests using predicted deleterious missense and loss-of-function variants. Statistical significance was assessed using permutation-corrected binomial testing. An independent validation was conducted in the UK Biobank. Results: Loss-of-function variants in known CRC tumor suppressor genes were significantly enriched in SAYO cases. Gene-level analyses identified MEIKIN as a novel EOCRC susceptibility candidate (p value = 1.0 × 10⁻⁷), with supporting enrichment of deleterious missense and loss-of-function variants in distal colon cancer cases from the UK Biobank. Additional genes (STK25, PGBD4, DIRAS3, ATG3, RPS6KA4, and DDX42) demonstrated borderline significance, implicating pathways related to kinetochore assembly, autophagy regulation, and immune signaling. Both predicted gain-of-function and loss-of-function variants contributed to the EOCRC risk, supporting heterogeneous mechanisms of CRC pathogenesis. Conclusions: This study identified novel candidate risk genes for EOCRC, underscoring the role of rare variants and expanding our understanding of the genetic architecture of CRC. Future studies should include functional validation and replication studies on other ancestries to confirm and extend these results. Full article

Background: In this study, we attempted to compare the bacteriology of chronic rhinosisusitis (CRS) with and without nasal polyps between geriatric and adult patients. Methods: This retrospective cross-sectional study included 751 patients with CRS who underwent bilateral primary functional endoscopic sinus surgery. Before surgery, swab samples were collected from the middle meatus for bacterial cultures using cotton-tipped sticks. Subjects were divided into adult (20 to 64 years, n = 683) and elderly (65 years, n = 68) groups. The results of the bacteria culture were analyzed according to age group and the presence of nasal polyps. Results: The bacterial culture rate was higher in geriatric patients (55.9%) than in adults (44.9%), but the difference was not statistically significant. However, geriatric patients showed a higher bacterial culture rate (57.6%) than adult patients (29.6%) without nasal polyps. This difference was statistically significant. Conclusions: Geriatric patients with CRS exhibited higher bacterial culture rates, particularly on the non-polyp side. These findings suggest a possible age-related susceptibility to microbial colonization, underscoring the need for age-specific infection management strategies. Full article

Background/Objectives: Ulcerative colitis (UC) is a chronic inflammatory bowel disease that significantly increases the colorectal cancer (CRC) risk. This study used nationwide data on intractable diseases to clarify the clinical epidemiology of UC-related CRC in Japan. Methods: Patients diagnosed with UC between FY 2003 and 2011 were included. The relative incidence ratio (RR) was calculated using the standardized incidence ratio from the National Cancer Registry. To compare prognostic factors, outcomes were evaluated using the Cox proportional hazards model analysis for cancer occurrence, and a prognostic prediction model was developed using machine learning. Results: Among 78,556 patients with UC, CRC was identified in 141 patients. The RR of CRC peaked in both males and females in the 25–39 age group. Univariate analysis revealed several risk factors, including pseudo-polyps observed during endoscopy (hazard ratio 2.92, p = 0.001), abnormal crypt architecture (hazard ratio 3.14, p < 0.001), and dysplasia (hazard ratio 11.31, p < 0.001) in biopsy. Conversely, 5-ASA was associated with reduced CRC risk (hazard ratio 0.36, p = 0.003). The machine learning model categorized patients into three groups, demonstrating that the group with the highest number of patients with pancolitis had a significantly higher risk of CRC than did the other groups. Conclusions: Pseudo-polyps and dysplasia represent CRC risk factors in patients with UC. Additionally, machine learning analysis indicates that pancolitis in individuals in their 50s increases the risk of colon cancer, while proctitis in those in their 30s raises rectal cancer risk. These findings aim to enhance early detection and improve prevention efforts for UC-related CRC. Full article

Sessile serrated lesions (SSLs) are well-known precursors of colorectal cancer in the general population, but their role in inflammatory bowel disease (IBD) is less clear. This narrative review summarizes what is known about the prevalence, molecular features, endoscopic detection, malignant potential, and management of SSLs in patients with IBD, highlighting where evidence supports action nowadays and where prospective studies are urgently needed. IBD-associated colorectal cancer has long been considered a consequence of the inflammation–dysplasia–carcinoma sequence, distinct from the conventional adenoma–carcinoma pathway. Increasing evidence, however, suggests that the serrated pathway, typically characterized by SSLs and traditional serrated adenomas (TSAs), may also contribute to IBD-related oncogenesis. This review synthesizes histopathological, molecular, endoscopic, and clinical data on SSLs in patients with IBD, with contextual reference to TSAs, sessile serrated lesions with dysplasia, and serrated epithelial change only when relevant to their interpretation or risk stratification. SSLs are now more frequently identified in IBD surveillance, especially in ulcerative colitis and the proximal colon, although prevalence estimates remain heterogeneous due to evolving definitions and significant interobserver variability. Molecular studies indicate that IBD-associated serrated lesions often harbor BRAF mutations but display a lower CpG island methylator phenotype than their sporadic counterparts, suggesting an inflammation-modified biology. While most hyperplastic polyps and non-dysplastic SSLs appear to pose limited neoplastic risk, dysplastic serrated lesions carry a markedly higher likelihood of synchronous or metachronous advanced neoplasia. Advances in high-definition endoscopy and chromoendoscopy improve the detection of these subtle, mucus-capped, flat lesions, while endoscopic resection is nowadays feasible in expert hands. Future priorities should include prospective multicenter cohorts integrating molecular profiling to refine surveillance strategies. Full article