Narrow Band Imaging Endoscopy Research Articles

Accuracy of Narrow-Band Imaging-Guided Histopathology and Ki-67 Index in Head and Neck Carcinoma

ABSTRACT As per Globocan 2012, every year the incidence of head and neck cancer is 683235/1000000 with a mortality of around 375665/1000000 thus being the sixth cause of cancer death throughout the world. Head and neck cancer includes cancer of the nasopharynx, oropharynx, hypopharynx, larynx, and oral cavity. Early diagnosis of head and neck cancer is very challenging, hence detecting mucosal lesions at an early stage decreases mortality thereby improving overall survival, disease-free survival, and quality of life. Out of different diagnostic modalities, narrow-band imaging (NBI) combined with endoscopic techniques can provide a promising diagnostic tool in detecting early lesions of head and neck cancer. Numerous studies have shown that Ki-67 is a good prognostic marker in oral cancers. Our study aims to evaluate the diagnostic accuracy of NBI and combine the Ki-67 index to diagnose head and neck cancer. Materials and Methods: All patients were first examined under white light and then under NBI endoscopy, and a biopsy was obtained from suspected lesions and sent for histopathological examination (HPE) and Ki-67 index. Results: Eighty patients were examined out of which, 68 patients having lesions in the oral cavity, oropharynx, larynx, and hypopharynx were examined. The rate of detecting cancerous lesion by white light and NBI were respectively 92% and 100% for oral cavity lesions, 69% and 100% for oropharyngeal lesions, 38% and 100% for hypopharyngeal lesions, and 37% and 100% for laryngeal carcinoma. However, we have found no significant difference in detecting T2-T4 tumors. Hence, we concluded that NBI mode can be a significantly better diagnostic tool than white light mode in detecting early mucosal cancer in head and neck cancer. Conclusion: We have concluded that NBI combined with Ki-67 estimation is a very promising tool that helps in the early diagnosis of mucosal lesions in head and and neck cancer.

Value of quantitative microsurface structure analysis for evaluating the invasion depth of type 0-II early gastric cancer.

The microsurface structure reflects the degree of damage to the glands, which is related to the invasion depth of early gastric cancer. To evaluate the diagnostic value of quantitative microsurface structure analysis for estimating the invasion depth of early gastric cancer. White-light imaging and narrow-band imaging (NBI) endoscopy were used to visualize the lesions of the included patients. The area ratio and depth-predicting score (DPS) of each patient were calculated; meanwhile, each lesion was examined by endoscopic ultrasonography (EUS). Ninety-three patients were included between 2016 and 2019. Microsurface structure is related to the histological differentiation and progression of early gastric cancer. The receiver operating characteristic curve showed that when an area ratio of 80.3% was used as a cut-off value for distinguishing mucosal (M) and submucosal (SM) type 0-II gastric cancers, the sensitivity, specificity, and accuracy were 82.9%, 80.2%, and 91.6%, respectively. The accuracies for distinguishing M/SM differentiated and undifferentiated early gastric cancers were 87.4% and 84.8%, respectively. The accuracy of EUS for distinguishing M/SM early gastric cancer was 74.9%. DPS can only distinguish M-SM1 (SM infiltration <500 μm)/SM (SM infiltration ≥500 μm) with an accuracy of 83.8%. The accuracy of using area ratio for distinguishing 0-II early gastric cancers was better than those of using DPS and EUS (P < 0.05). Quantitative analysis of microsurface structure can be performed to assess M/SM type 0-II gastric cancer and is expected to be effective for judging the invasion depth of gastric cancer.

A Comprehensive Study on the Digestive Endoscopic Technique and Narrow-Band Imaging for Early Gastric Cancer Screening

Objective: To explore the implementation of gastrointestinal endoscopy technology and endoscopic narrow-band imaging (NBI) in the early screening of gastric cancer and to observe and study their application effects. Methods: During the period from March 2023 to August 2023, 312 patients who received gastroscopy in the Kunming Guandu District People’s Hospital were selected, and they underwent both conventional gastroscopy and endoscopic NBI, with clinicopathological tissue biopsy serving as the gold standard. The application value for early screening of gastric cancer was observed and analyzed. Results: The scoring data showed that the clarity of gastric mucosal glandular tube structure, microvascular structure clarity, and lesion contour scoring data of conventional gastroscopy were lower than those of the NBI technology (P &lt; 0.05). The screening rate of pathological biopsy in 312 patients was 18.59% (58 cases). Conventional gastroscopy showed a screening rate of 11.53% (36 cases), while NBI technology examined a screening rate of 17.63% (55 cases), and the two-by-two comparison of the screening rate data of the three groups was not statistically significant (P &gt; 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of conventional gastroscopy appeared to be lower than those of NBI technology (P &lt; 0.05). Conclusion: In the early screening of gastric cancer, endoscopic NBI technology can be applied to patients. Compared with conventional gastroscopy, it provides a clearer visualization of the structure of the gastric mucosal glandular structure and microvascular structure, with a certain screening rate. Additionally, its sensitivity, specificity, accuracy, positive predictive value, and negative predictive value are higher, demonstrating outstanding effectiveness.

Clinical significance of type IV vascularization of laryngeal lesions according to the Ni classification

BackgroundScattered, small, dot-like intraepithelial papillary capillary loops (IPCLs) represent type IV epithelial vascularization according to “Ni classification” and are considered to be nonmalignant. According to the European Laryngological Society classification, these loops are malignant vascular changes. This contradiction has high clinical importance; therefore, clarification of the clinical significance of type IV vascularization according to the Ni classification is needed.MethodsThe study was performed between June 2015 and December 2022. All recruited patients (n = 434) were symptomatic, with macroscopic laryngeal lesions (n = 674). Patients were investigated using the enhanced endoscopic methods of narrow band imaging (NBI) and the Storz Professional Image Enhancement System (IMAGE1 S). The microvascular patterns in the lesions were categorized according to Ni classification from 2011 and all lesions were examined histologically.ResultsA total of 674 lesions (434 patients) were investigated using flexible NBI endoscopy and IMAGE1 S endoscopy. Type IV vascularization was recognized in 293/674 (43.5%) lesions. Among these 293 lesions, 178 (60.7%) were benign (chronic laryngitis, hyperplasia, hyperkeratosis, polyps, cysts, granulomas, Reinkeho oedema and recurrent respiratory papillomatosis); 9 (3.1%) were squamous cell carcinoma; 61 (20.8%) were mildly dysplastic, 29 (9.9%) were moderately dysplastic, 14 (4.8%) were severe dysplastic and 2 (0.7%) were carcinoma in situ. The ability to recognize histologically benign lesions in group of nonmalignant vascular pattern according to Ni (vascularization type I-IV) and distinguish them from precancers and malignancies was with accuracy 75.5%, sensitivity 54.4%, specificity 94.4%, positive predictive value 89.6% and negative predictive value 69.9%.ConclusionLaryngeal lesions with type IV vascularization as defined by Ni present various histological findings, including precancerous and malignant lesions. Patients with type IV vascularization must be followed carefully and, in case of progression mucosal lesion microlaryngoscopy and excision are indicated.

Carbon footprint and cost reduction by endoscopic grading of gastric intestinal metaplasia using narrow-band imaging.

Gastric intestinal metaplasia (GIM) is a high-risk factor for the development of gastric cancer. Narrow-band imaging (NBI) enables endoscopic grading of GIM (EGGIM). In the era of climate change, gastrointestinal endoscopists are expected to reduce greenhouse gas emissions and medical waste. Based on the diagnostic performance of NBI endoscopy, this study measured the environmental impact and reduced cost of implementing EGGIM during gastroscopy. Using NBI endoscopy in 242 patients, EGGIM classification and operative link on GIM (OLGIM) staging were prospectively performed in five different areas (lesser and greater curvatures of the corpus and antrum, and the incisura angularis). We estimated the environmental impact and cost reduction of the biopsy procedures and pathological processing if EGGIM were used instead of OLGIM. The diagnostic accuracy of NBI endoscopy for GIM was 93.0-97.1% depending on the gastric area. When a high EGGIM score ≥5 was the cut-off value for predicting OLGIM stages III-IV, the area under the curve was 0.862, sensitivity was 81.9%, and specificity was 90.4%. The reduction in the carbon footprint by EGGIM was -0.4059kg carbon dioxide equivalents per patient, equivalent to 1 mile driven by a gasoline-powered car. The cost savings were calculated to be $47.36 per patient. EGGIM is a reliable method for identifying high-risk gastric cancer patients, thereby reducing the carbon footprint and medical costs in endoscopy practice.

Routine image-enhanced endoscopic surveillance for metachronous esophageal squamous cell neoplasms in head and neck cancer patients.

Esophageal squamous cell neoplasms (ESCNs) are common second primary tumors in patients with head and neck cancer. Image-enhanced endoscopy (IEE) with Lugol chromoendoscopy or magnifying narrow-band imaging both increase the detection of early ESCNs. No evidence-based ESCN surveillance program for head and neck cancer patients without a history of synchronous ESCNs exists. We aimed to evaluate the performance of an IEE surveillance program with magnifying narrow-band imaging endoscopy and Lugol chromoendoscopy. From April 2016, we routinely used IEE with magnifying narrow-band imaging and Lugol chromoendoscopy to evaluate patients with head and neck cancer history. All patients who were negative for ESCNs at the first surveillance endoscopy and received at least 2 IEEs through December 2019 were included. Demographic profiles, clinical data, cancer characteristics, IEE results and pathology reports were analyzed. A total of 178 patients were included. Only 4 patients (2.2%) developed metachronous ESCNs during follow-up, all of whom received curative resection treatment. The interval for the development of metachronous ESCNs was 477 to 717 days. In multivariate Firth logistic regression and Kaplan‒Meier survival curve analysis, Lugol's voiding lesion type C had an increased risk of esophageal cancer development (adjusted odds ratio = 15.71; 95% confidence interval, 1.33-185.87, p = 0.029). Eight patients died during the study period, and none of them had metachronous ESCNs. IEE with magnifying narrow-band imaging and Lugol chromoendoscopy is an effective surveillance program in head and neck cancer patients without a history of ESCNs. Annual surveillance can timely detect early ESCNs with low ESCN-related mortality.

Artificial intelligence system for the detection of Barrett's esophagus.

Barrett's esophagus (BE), which has increased in prevalence worldwide, is a precursor for esophageal adenocarcinoma. Although there is a gap in the detection rates between endoscopic BE and histological BE in current research, we trained our artificial intelligence (AI) system with images of endoscopic BE and tested the system with images of histological BE. To assess whether an AI system can aid in the detection of BE in our setting. Endoscopic narrow-band imaging (NBI) was collected from Chung Shan Medical University Hospital and Changhua Christian Hospital, resulting in 724 cases, with 86 patients having pathological results. Three senior endoscopists, who were instructing physicians of the Digestive Endoscopy Society of Taiwan, independently annotated the images in the development set to determine whether each image was classified as an endoscopic BE. The test set consisted of 160 endoscopic images of 86 cases with histological results. Six pre-trained models were compared, and EfficientNetV2B2 (accuracy [ACC]: 0.8) was selected as the backbone architecture for further evaluation due to better ACC results. In the final test, the AI system correctly identified 66 of 70 cases of BE and 85 of 90 cases without BE, resulting in an ACC of 94.37%. Our AI system, which was trained by NBI of endoscopic BE, can adequately predict endoscopic images of histological BE. The ACC, sensitivity, and specificity are 94.37%, 94.29%, and 94.44%, respectively.

Application of narrow band imaging and Lugol's iodine staining in screening for nasopharyngeal carcinoma

BackgroundTo investigate the diagnostic value of conventional white light endoscopy (WLE), narrow band imaging (NBI) endoscopy, and Lugol's iodine staining under WLE (endoscopic iodine staining) in the screening and early diagnosis of nasopharyngeal carcinoma.MethodsPatients with nasopharyngeal lesions requiring biopsy attending the Department of Otolaryngology Head and Neck Surgery in our hospital between January 2021 and April 2023 were included in this study. Before biopsy, all subjects underwent conventional WLE, NBI endoscopy, and endoscopic iodine staining. On WLE, according to nasopharyngeal lesion morphology and color, patients were diagnosed with nasopharyngeal carcinoma ( +) or chronic hyperplastic nasopharyngitis (-). On NBI endoscopy, according to nasopharyngeal lesion vascular morphology, patients with type V manifestations (nasopharyngeal carcinoma) were categorized as NBI ( +) and patients with type I-IV manifestations (chronic hyperplastic nasopharyngitis) were categorized as NBI (-). Endoscopic iodine staining (1.6% Lugol's iodine solution) was positive ( +) if the mucosal surface was brown with no white patches, or negative (-) if there was no or light brown staining of the mucosal surface. Patients were divided into 2 groups based on histopathological diagnosis: nasopharyngeal carcinoma or chronic hyperplastic nasopharyngitis. Endoscopic diagnoses were compared with histopathological findings. The diagnostic performance of WLE, NBI endoscopy and endoscopic iodine staining for nasopharyngeal carcinoma were determined.ResultsThis study included 159 patients. On histopathology, 29 patients were diagnosed with nasopharyngeal carcinoma, and 130 patients were diagnosed with chronic hyperplastic nasopharyngitis. There were no significant differences in the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the receiver operating characteristic (ROC) curve (AUC) of conventional WLE, NBI endoscopy or endoscopic iodine staining for differentiating nasopharyngeal carcinoma and chronic hyperplastic nasopharyngitis. The diagnostic performance of the combination of conventional WLE, NBI endoscopy and endoscopic iodine staining was significantly improved compared to any procedure alone.ConclusionsConventional WLE, NBI endoscopy or endoscopic iodine staining had good diagnostic performance for differentiating nasopharyngeal carcinoma and chronic hyperplastic nasopharyngitis. In particular, NBI endoscopy and endoscopic iodine staining alone or combined had clinical utility for identifying patients with nasopharyngeal lesions that are eligible for a watch-and-wait strategy.

Automatic delineation of laryngeal squamous cell carcinoma during endoscopy

White Light (WL) and Narrow Band Imaging (NBI) endoscopy are widely used to assess the superficial spreading of laryngeal squamous cell carcinoma (LSCC). However, the analysis of images requires a high level of attention and extensive clinical expertise, leading to inter-clinician variability on the assessment of tumor margins. Computer-aided segmentation can automate the identification of LSCC margins, supporting clinicians in this challenging task. In this paper, we present SegMENT-Plus, a Deep Learning segmentation convolutional network specifically developed and optimized for accurate delineation of LSCC. SegMENT-Plus uses EfficienstNetB5 as encoder with a new modified Atrous Spatial Pyramid Pooling (m-ASPP) block that integrates Channel Block Attention Module (CBAM) and Squeeze Excitation (SE). In this new architecture, CBAM extracts local and global LSCC features from the encoder, while the SE block refines cancer segmentation on each dilated convolution output. SegMENT-Plus was trained and evaluated on a multi-center dataset including clinical data from three different hospitals. A total of 4289 annotated laryngeal images from 766 patients were included in this study. The experiments showed that SegMENT-Plus achieved a Dice Similarity Coefficient (DSC) between 81.4% and 84.9% and an Intersection over Union (IOU) between 81.8% and 85.7% on the data from the different hospitals, attesting its high performance and generalization capability. The proposed segmentation architecture also demonstrated statistically significant improvement in DSC and IoU compared to other state of the art architectures, showing that this work is a concrete foundation towards a clinical system for the automatic delineation of LSCC margins in endoscopic images.

Retracted: Diagnostic Value of Endoscopic Narrow-Band Imaging Technique in Early Gastric Cancer and Precancerous Lesions.

[This retracts the article DOI: 10.1155/2022/9205150.].

Vocal cord leukoplakia classification using deep learning models in white light and narrow band imaging endoscopy images.

Accurate vocal cord leukoplakia classification is critical for the individualized treatment and early detection of laryngeal cancer. Numerous deep learning techniques have been proposed, but it is unclear how to select one to apply in the laryngeal tasks. This article introduces and reliably evaluates existing deep learning models for vocal cord leukoplakia classification. We created white light and narrow band imaging (NBI) image datasets of vocal cord leukoplakia which were classified into six classes: normal tissues (NT), inflammatory keratosis (IK), mild dysplasia (MiD), moderate dysplasia (MoD), severe dysplasia (SD), and squamous cell carcinoma (SCC). Vocal cord leukoplakia classification was performed using six classical deep learning models, AlexNet, VGG, Google Inception, ResNet, DenseNet, and Vision Transformer. GoogLeNet (i.e., Google Inception V1), DenseNet-121, and ResNet-152 perform excellent classification. The highest overall accuracy of white light image classification is 0.9583, while the highest overall accuracy of NBI image classification is 0.9478. These three neural networks all provide very high sensitivity, specificity, and precision values. GoogLeNet, ResNet, and DenseNet can provide accurate pathological classification of vocal cord leukoplakia. It facilitates early diagnosis, providing judgment on conservative treatment or surgical treatment of different degrees, and reducing the burden on endoscopists.

The Effectiveness of White Light Endoscopy Combined With Narrow Band Imaging Technique Using Ni Classification in Detecting Early Laryngeal Carcinoma in 114 Patients: Our Clinical Experience

By displaying tumor-specific neoangiogenesis, narrow band imaging (NBI), a novel imaging approach, enhances the diagnosis of head and neck cancers and makes it more accurate OBJECTIVE: To determine the effect of NBI in combination with white light endoscopy (WLE) for diagnosis of preneoplastic or neoplastic laryngeal cancers according to Ni classification and to conclude if higher Ni classification and tumor stage are related. We enrolled 114 patients with various laryngeal cancer between December 2018 and June 2021. Patients were examined with WLE and NBI. Squamous cell carcinoma (SCC) accounted for 46 cases, benign lesions 30 cases, and nondysplastic, low-grade, and severe dysplasias for 38 cases. Based on characteristics of the intraepithelial papillary capillary loop (IPCL), endoscopic NBI results were divided into five categories (I, II, III, IV, and V). Type I-IV are regarded to be benign, while type V is considered to be cancerous. An incisional biopsy was conducted to assess histopathology, and the histopathology was compared to the NBI results. We assessed the negative predictive value (NPV), positive predictive value (PPV), specificity, and sensitivity for WLE alone and WLE combined with NBI. Analyses were conducted using SPSS software version 26. The WLE combined with NBI showed excellent sensitivity (96%) compared to WLE (86.4%). Specificity was higher in the WLE combined with NBI (96.4%) than WLE alone (91.7%). WLE combined with NBI saw a NPV of 89% as compared with WLE with 88%. WLE and WLEin combination with NBI, recorded a PPV of 90% and 98%, respectively. The accuracy of detecting laryngeal cancer increases when WLE and NBI are combined. Combined NBI with WLE remains highly sensitive to early glottis cancer. Accuracy of preoperative NBI was high. In the diagnosis of laryngeal cancer, a higher Ni classification closely correlates with the late stages of the glottis tumor.

The importance of preoperative and perioperative Narrow Band Imaging endoscopy in the diagnosis of pre-tumor and tumor lesions of the larynx.

Narrow band imaging (NBI) is an endoscopic imaging method intended for the diagnosis of mucosal lesions of the larynx that are not visible in white-light endoscopy, but are typical of pre-tumor and tumor lesions of the larynx. To compare preoperative/perioperative white light endoscopy and NBI endoscopy with the results of histopathological examinations in pre-tumor and tumor lesions of the larynx. A prospective study, over a period of five years (5/2018-5/2023), included 87 patients with laryngeal lesions aged 24-80 years. We evaluated preoperative/ perioperative white light and NBI endoscopy, established a working prehistological diagnosis, and compared this with the definitive histopathological results of laryngeal biopsies. In relation to the definitive histology score, a statistically significant correlation was found between the evaluation of the finding and the definitive histology for preoperative and perioperative white light endoscopy and NBI endoscopy (p < 0.001). Both methods showed higher precision when used perioperatively. NBI endoscopy is an optical method that allows us to improve the diagnosis of laryngeal lesions, perform a controlled perioperative biopsy, and refine the surgical scope. The NBI endoscopy is a suitable method for the diagnosis of early cancerous lesions of the larynx. The use of preoperative/perioperative NBI endoscopy allowed us to achieve a high level of agreement correlation (p < 0.001) between the prehistological working diagnosis and the final histopathological result. The NBI method proves its application in the diagnosis of pre-tumor and tumor lesions of the larynx.

Gastrointestinal: Peutz-Jeghers syndrome with a novel frameshift mutation in STK 11 gene observed by magnifying narrowband imaging endoscopy.

Gastrointestinal: Peutz-Jeghers syndrome with a novel frameshift mutation in STK 11 gene observed by magnifying narrowband imaging endoscopy.

Microarchitectures of Barrett's esophagus associated with DNA methylation status.

Aim: DNA methylation is involved in esophageal adenocarcinoma (EAC) and Barrett's esophagus (BE). Microarchitectures of on-neoplastic BE associated with DNA methylation status were examined using magnifying narrow-band imaging (NBI) endoscopy. Patients and methods: Using biopsies from non-neoplastic BE without cancer (n=66; N group), with EAC (n=27; ADJ group) and EAC tissue (n=22; T group), methylation of N33, DPYS, SLC16A12, miR124a3 andmiR34bc genes were quantified. MagnifyingNBI features of non-neoplastic BE were classified according to their morphologies. Results: TheADJ and T groups presented higher DNA methylation compared with theN group. Magnifying NBI endoscopic features of non-neoplastic BE also correlated with DNA methylation as an independent factor. Conclusion: Microarchitectures of BE visualized by magnifying NBI endoscopy correlated with DNA methylation.

Endoscopic features of gastric neuroendocrine carcinoma.

The endoscopic features of gastric neuroendocrine carcinoma (G-NEC) have not been clarified; therefore, they were investigated in relation to clinicopathological findings. Consecutive patients with G-NECs who had undergone endoscopic or surgical resection at our institution between January 2005 and March 2022 were included in this retrospective study. The endoscopic and clinicopathological findings of the lesions were analyzed to provide information of diagnostic value. In addition, cases of gastric neuroendocrine tumor (G-NET) and common-type gastric adenocarcinoma treated in the same study period were identified to compare the endoscopic findings between each G-NEC versus G-NET, and G-NEC versus common-type gastric adenocarcinoma. Patients with common-type gastric adenocarcinoma were matched for age, sex, tumor size, and depth of tumor invasion in 1:3 ratio. Among 15 patients with 15 G-NECs, submucosal tumor-like marginal elevation (87%), adherent white coat (67%), and ulceration with a distinct border (60%) were characteristic endoscopic findings in white-light images. Magnifying narrow-band imaging endoscopy revealed an absent microsurface (MS) pattern plus disrupted irregular microvessel (MV) in five (71%) of seven cases with evaluable MS and MV patterns. The area with an absent MS pattern plus disrupted irregular MV corresponded to the histological finding of NEC component in all five cases. These endoscopic features were all significantly more frequent in G-NECs than G-NETs (n=22) or common-type gastric adenocarcinomas (n=45). These endoscopic features should be taken into consideration to increase the index of suspicion and to improve the accuracy of target biopsies for G-NEC.

Comparison of narrow-band imaging with autofluorescence imaging for endoscopic detection of squamous cell carcinoma of the tonsil

PurposeEarly detection of mucosal neoplastic lesions is crucial for a patient’s prognosis. This has led to the development of effective optical endoscopic diagnostic methods such as narrow band imaging (NBI) and autofluorescence (AFI). Independent of each other, both of these methods were proven useful in the detection of mucosal neoplasias. There are limited reported data comparing both methods for oropharyngeal cancer diagnostics. The aim of the study was to compare NBI and AFI endoscopic visualization of signs in identifying tonsillar squamous cell carcinoma (SCC) and assessing its extent and to determine whether the score was related to the evaluator’s experience.MethodsPatients with tonsillar SCC underwent endoscopic pharyngeal examination using NBI and AFI. Fiftyseven video sequences of examinations of lesions proven to be SCC were evaluated by three reviewers. The accuracy of determination of lesion extent and visualization of its endoscopic signs of malignancy were evaluated.ResultsEndoscopic visualization of tumour spread was significantly better using AFI than NBI (p = 0.0003). No significant difference was found between NBI and AFI in the visualization of endoscopic malignancy determining signs (p = 0.1405). No significant difference was found among the three reviewers in the visualization of tumour spread and for identifying malignancy-determining signs in NBI endoscopy or AFI endoscopy.ConclusionsThe results show that AFI obtained better results for assessing the extent of tonsillar cancers than NBI. Both methods were proven to be equal in the visualization of endoscopic malignancy-determining signs. Both are useful even for less experienced evaluators.

Gastrointestinal: Unusual pathology of an anorectal lesion mimicking a benign laterally spreading tumor.

A 70-year-old woman was referred to our institution for the diagnosis and treatment of an anorectal lesion detected on colonoscopy performed at a previous hospital for hematochezia. Colonoscopy revealed a 32-mm flat elevated lesion in the lower rectum with an anal component extending to the dentate line (Fig. 1a). Chromoendoscopy with indigo carmine spraying demonstrated a papillary surface (Fig. 1b). Magnifying endoscopy with narrowband imaging (NBI) displayed an irregular vessel resembling the intrapapillary capillary loop (IPCL) of the Japan Esophageal Society Classification Type B1 (Fig. 1c). Magnifying endoscopy with 0.05% crystal violet staining revealed the absence of discernible glandular ducts, hindering the evaluation of the pit pattern (Fig. 1d). The endoscopic appearance resembled a large adenoma or condyloma acuminatum; however, the absence of a pit pattern indicated that the lesion was covered with squamous epithelium and not columnar. Moreover, the irregular vessel pattern suggested a neoplastic lesion. Based on these observations, the lesion was diagnosed as a neoplasm originating from the squamous epithelium of the anal canal. Thus, we performed endoscopic submucosal dissection for complete elimination. Histological examination revealed a papillary growing squamous cell carcinoma (SCC) exhibiting low-grade and high-grade atypia and abundant dilated vessels (Fig. 2a). The tumor extended from the anal transitional zone (ATZ) to the rectum and entrapped the rectal crypts (Fig. 2b). Some tumor cells had a clear cytoplasm, indicative of koilocytosis (Fig. 2c), and positive p16 immunohistochemical staining suggested human papillomavirus (HPV) infection (Fig. 2d). The final diagnosis was HPV-associated SCC in situ originating from the ATZ with rectal extension. Anal canal cancer (ACC) is a rare disease that accounts for only 0.3% of all malignancies and is strongly associated with high-risk HPV (HPV-16 and HPV-18). This case was unusual because of the extensive infiltration of the columnar epithelium. Therefore, it might be misidentified as a rectal adenoma. Early ACC shows irregular vessel patterns reminiscent of esophageal SCC on magnified endoscopic NBI, which has been reported to be useful in diagnosing ACC. However, laterally spreading tumor (LST) can exhibit similar irregular capillary vessels. The difference in endoscopic appearance between ACC and LST can be explained by their different epithelial anatomies. ACC develops in the squamous cell epithelium and has no orifice or crypt. In contrast, LST originates from the columnar epithelium and has crypt openings. Condyloma acuminatum has a similar endoscopic appearance but with milder vascular dilatation and caliber changes. In conclusion, HPV-associated anal canal cancer can be suspected in papillary tumors with an irregular esophageal SCC-like vascular pattern and absence of glandular structures. Piecemeal endoscopic mucosal resection can be selected for large adenomas; conversely, en bloc resection is the preferred method for ACC to mitigate the risk of recurrence. To ensure the implementation of appropriate treatment, more attention should be paid to lesions extending along the anal canal to the rectum.

Diagnosis of nasopharyngeal carcinoma with convolutional neural network on narrowband imaging

Objective:To evaluate the diagnostic accuracy of the convolutional neural network（CNN） in diagnosing nasopharyngeal carcinoma using endoscopic narrowband imaging. Methods:A total of 834 cases with nasopharyngeal lesions were collected from the People's Hospital of Guangxi Zhuang Autonomous Region between 2014 and 2016. We trained the DenseNet201 model to classify the endoscopic images, evaluated its performance using the test dataset, and compared the results with those of two independent endoscopic experts. Results:The area under the ROC curve of the CNN in diagnosing nasopharyngeal carcinoma was 0.98. The sensitivity and specificity of the CNN were 91.90% and 94.69%, respectively. The sensitivity of the two expert-based assessment was 92.08% and 91.06%, respectively, and the specificity was 95.58% and 92.79%, respectively. There was no significant difference between the diagnostic accuracy of CNN and the expert-based assessment （P=0.282, P=0.085）. Moreover, there was no significant difference in the accuracy in discriminating early-stage and late-stage nasopharyngeal carcinoma（P=0.382）. The CNN model could rapidly distinguish nasopharyngeal carcinoma from benign lesions, with an image recognition time of 0.1 s/piece. Conclusion:The CNN model can quickly distinguish nasopharyngeal carcinoma from benign nasopharyngeal lesions, which can aid endoscopists in diagnosing nasopharyngeal lesions and reduce the rate of nasopharyngeal biopsy.

A comparison of the efficacy of narrow band imaging and contact endoscopy in an early diagnosis of squamous malignancies of the upper aerodigestive tract

BackgroundThis study aims to compare the efficacy of narrow band imaging (NBI) endoscopy and contact endoscopy in early diagnosis of squamous malignancies of upper aerodigestive tract. MethodsThis study was of 18 months duration, sample size 50, and carried out at tertiary care hospital. The patients were subjected initially to NBI endoscopy followed by contact endoscopy. Thereafter, the lesion was biopsied and subjected to histopathological examination as is done routinely. The images obtained were analyzed based on criteria proposed by earlier studies and compared with histopathological examination as gold standard. ResultsThe sensitivity, specificity, and negative predictive values of NBI in early diagnosis of squamous malignancies of upper aerodigestive tract were high and better than contact endoscopy. ConclusionEndoscopic NBI is a noninvasive and promising tool used for in vivo differentiation between malignant and nonmalignant lesions of upper aerodigestive tract by using morphology of mucosal capillaries and is more efficacious than contact endoscopy. It can be employed as part of routine ENT examination in outpatient departments; however, it has got a learning curve associated with it.