Histological features responsible for brownish epithelium in squamous neoplasia of the esophagus by narrow band imaging

Efficacy of endoscopic surveillance for pharyngeal mucosa during endoscopic resection for pharyngeal carcinoma: a multicenter prospective study

INTRODUCTION

Since patients with pharyngeal squamous cell carcinoma (SCC) often have multiple pharyngeal lesions, evaluation of pharyngeal lesions before endoscopic resection (ER) is important. However, detailed endoscopic observation of the entire pharyngeal mucosa under conscious sedation is difficult. We examined the usefulness of endoscopic surveillance with narrow band imaging (NBI) and lugol staining for detection of pharyngeal sublesions during ER for pharyngeal SCC under general anesthesia (endoscopic surveillance during treatment; ESDT).

METHODS

From January 2021 through June 2022, we examined 78 patients who were diagnosed with superficial pharyngeal SCC and underwent ER. They underwent the ESDT and for patients who were diagnosed with new lesions of pharyngeal SCC or high-grade dysplasia (HGD) that were not detected in the endoscopic examination before treatment, ER were performed simultaneously for new lesions and the main lesions. The primary endpoint of this study was the detection rate of new lesions of pharyngeal SCC or HGD in the ESDT.

RESULTS

Fifteen of the 78 patients were diagnosed as having undetected new pharyngeal lesions in the ESDT and 10 (12.8%) (95% CI 6.9-22.2%) were histopathologically confirmed to have new lesions of pharyngeal SCC or HGD. Among the 13 lesions of SCC or HGD, 8 were found by NBI observation; however, 5 were undetectable using NBI but detectable by lugol staining. All of the 13 lesions had endoscopic findings of pink color sign on lugol staining.

CONCLUSIONS

Endoscopic surveillance for pharyngeal sublesions during ER for pharyngeal SCC is feasible and useful.

Multiple foci of dilated vessels as a new predictor of metachronous esophageal cancer

OBJECTIVES

Prediction of the risk of esophageal squamous cell carcinoma (SCC) by endoscopic findings without iodine staining, which is irritating to the esophagus, would be beneficial. In a previous retrospective study, we found that multiple foci of dilated vascular areas (MDV) of the esophageal mucosa, seen in narrow-band imaging (NBI)/blue laser imaging (BLI), are associated with iodine-unstained lesions and, thus, may be a predictor of esophageal SCC. This prospective study aimed to investigate the association between MDV and metachronous esophageal SCC.

METHODS

Patients with a history of endoscopic resection for esophageal SCC were included in the study. First, evaluation of the MDV using NBI or BLI was conducted during the initial endoscopy. The patients were then monitored for metachronous esophageal SCC by endoscopic surveillance. The association between the number of MDV and incidence of metachronous esophageal SCC was investigated.

RESULTS

From February 2018 to May 2019, 206 patients were enrolled and 201 patients were included in the analysis. Patients were followed up until October 2022. The median (interquartile range) endoscopic follow-up period was 1260 (1105-1348) days. The incidence of metachronous esophageal SCC at 2 years was 7.1% in patients with MDV ≤4 and 13.9% in patients with MDV ≥5 (P < 0.01). In the multivariate analysis, MDV was an independent predictor of metachronous esophageal SCC, with an odds ratio (95% confidence interval) of 2.37 (1.06-5.31).

CONCLUSION

Multiple foci of dilated vascular area is a useful predictor for stratifying the risk of metachronous esophageal SCC.

Blue light imaging and linked color imaging as a screening mode for esophageal squamous cell carcinoma in high-risk patients: Multicenter randomized trial

OBJECTIVES

Blue light imaging (BLI) and linked color imaging (LCI) are superior to conventional white light imaging for detecting esophageal squamous cell carcinoma (ESCC). Hence, we compared their diagnostic performances in ESCC screening.

METHODS

This open-labeled, randomized controlled trial was performed at seven hospitals. Patients with a high risk of ESCC were randomly assigned to the BLI group (BLI followed by LCI) and LCI group (LCI followed by BLI). The primary end-point was the detection rate of ESCC in the primary mode. The main secondary end-point was its miss rate in the primary mode.

RESULTS

In total, 699 patients were enrolled. The detection rate of ESCC did not significantly differ between the BLI and LCI groups (4.0% [14/351] vs. 4.9% [17/348]; P = 0.565); however, the number of patients with ESCC tended to be smaller in the BLI group (19 vs. 30). Notably, the miss rate of ESCC was lower in the BLI group (26.3% [5/19] vs. 63.3% [19/30]; P = 0.012) and LCI detected no ESCCs missed by BLI. The sensitivity was higher in BLI (75.0% vs. 47.6%; P = 0.042); on the other hand, the positive predictive value in BLI tended to be lower (28.8% vs. 45.5%; P = 0.092).

CONCLUSIONS

The detection rates of ESCC did not significantly differ between BLI and LCI. Although BLI may have the potential to be advantageous over LCI for the diagnosis of ESCC, it is still unclear whether BLI is superior to LCI, and a further large-scale study is needed.

TRIAL REGISTRATION

Japan Registry of Clinical Trials (jRCT1022190018-1).

Human-Like Artificial Intelligent System for Predicting Invasion Depth of Esophageal Squamous Cell Carcinoma Using Magnifying Narrow-Band Imaging Endoscopy: A Retrospective Multicenter Study

INTRODUCTION

Endoscopic evaluation is crucial for predicting the invasion depth of esophagus squamous cell carcinoma (ESCC) and selecting appropriate treatment strategies. Our study aimed to develop and validate an interpretable artificial intelligence-based invasion depth prediction system (AI-IDPS) for ESCC.

METHODS

We reviewed the PubMed for eligible studies and collected potential visual feature indices associated with invasion depth. Multicenter data comprising 5,119 narrow-band imaging magnifying endoscopy images from 581 patients with ESCC were collected from 4 hospitals between April 2016 and November 2021. Thirteen models for feature extraction and 1 model for feature fitting were developed for AI-IDPS. The efficiency of AI-IDPS was evaluated on 196 images and 33 consecutively collected videos and compared with a pure deep learning model and performance of endoscopists. A crossover study and a questionnaire survey were conducted to investigate the system's impact on endoscopists' understanding of the AI predictions.

RESULTS

AI-IDPS demonstrated the sensitivity, specificity, and accuracy of 85.7%, 86.3%, and 86.2% in image validation and 87.5%, 84%, and 84.9% in consecutively collected videos, respectively, for differentiating SM2-3 lesions. The pure deep learning model showed significantly lower sensitivity, specificity, and accuracy (83.7%, 52.1% and 60.0%, respectively). The endoscopists had significantly improved accuracy (from 79.7% to 84.9% on average, P = 0.03) and comparable sensitivity (from 37.5% to 55.4% on average, P = 0.27) and specificity (from 93.1% to 94.3% on average, P = 0.75) after AI-IDPS assistance.

DISCUSSION

Based on domain knowledge, we developed an interpretable system for predicting ESCC invasion depth. The anthropopathic approach demonstrates the potential to outperform deep learning architecture in practice.

Beige mucosa observable under narrow-band imaging indicates the active sites of eosinophilic esophagitis

BACKGROUND AND AIM

The majority of patients with eosinophilic esophagitis (EoE) are likely to have observable features under narrow-band imaging, namely beige mucosa. However, the histological features and clinical implications of beige mucosa have not been investigated. The aim of this study was to determine whether beige mucosa could serve as an endoscopic marker for predicting active inflammatory sites of EoE.

METHODS

We retrospectively analyzed both the narrow-band images and biopsied specimens of 77 esophageal lesions from 35 consecutive patients with EoE. We divided these specimens into two groups: target biopsied specimens from beige mucosa (beige group) and specimens biopsied from non-beige mucosa (non-beige group). The number of eosinophils per high-powered field, thickness of the superficial differentiated cell layer, and depth of the hemoglobin component from the surface layer were compared between the two groups.

RESULTS

Forty-four out of the 45 specimens were diagnosed as histological active lesions in the beige group. The sensitivity, specificity, and overall accuracy of beige mucosa in predicting EoE activity were 97.8%, 96.9%, and 97.8%, respectively. Compared with the non-beige group, specimens in the beige group had a significantly thinner superficial differentiated cell layer.

CONCLUSIONS

Beige mucosa is associated with thinning of the normal superficial differentiated cell layer, and these histological changes in the active inflammatory sites of EoE could be recognized endoscopically as color differences. Beige mucosa may serve as an endoscopic indicator for predicting the histological activity of EoE.

Current status of endoscopic detection, characterization and staging of superficial esophageal squamous cell carcinoma

BACKGROUND

This review focuses on the current status of endoscopic detection, characterization and tumour category staging of oesophagealsquamous cell carcinoma.

DETECTION

The diagnostic yield of white-light imaging is limited and narrow-band imaging has demonstrated a better performance for detecting oesophageal cancer. Narrow-band imaging has also shown similar sensitivity and superior specificity to iodine staining.

CHARACTERIZATION

Accurate differentiation between cancerous and non-cancerous lesions can be achieved by magnifying narrow-band imaging or iodine staining with confirmation of a pink-colour sign. A per-patient analysis of a randomized study showed similar sensitivities, specificities and overall accuracies of magnifying narrow-band imaging and iodine staining of 82.2%, 95.1% and 91.2%, and 80.5%, 94.3% and 90.5%, respectively.

TUMOUR-STAGING

The diagnostic capability of endoscopic ultrasonography after conventional and narrow-band imaging in terms of tumour depth was evaluated in a multicentre prospective study. Endoscopic ultrasonography did not significantly improve the accuracy for distinguishing between mucosal or submucosal microinvasive cancer and deeper cancers from 72.9 to 74.0%, suggesting that additional endoscopic ultrasonography did not improve the diagnostic accuracy. In addition, endoscopic ultrasonography increased the incidence of overdiagnosis, defined as a diagnosis of cancer depth greater than the actual depth, by 6.6%. The risk of overdiagnosis by endoscopic ultrasonography was reconfirmed in two systematic reviews.

CONCLUSIONS

Narrow-band imaging is currently considered as the standard modality for the detection and characterization of oesophageal cancer. The risk of overdiagnosis should be considered when applying endoscopic ultrasonography for the evaluation of tumour invasion depth of superficial oesophageal squamous cell carcinoma.

Current Status of Mucosal Imaging with Narrow-Band Imaging in the Esophagus

Recent advances in endoscopic imaging of the esophagus have revolutionized the diagnostic capability for detecting premalignant changes and early esophageal malignancy. In this article, we review the practical application of narrow-band imaging focusing on diseases of the esophagus, including Barrett's esophagus, adenocarcinoma, and squamous cell carcinoma.

Diffuse xanthoma in early esophageal cancer: A case report

BACKGROUND

Gastrointestinal xanthomas are asymptomatic and infrequent non-neoplastic lesions that commonly occur in the stomach with Helicobacter pylori-associated gastritis and rarely in the esophagus. To date, there have been no reports of esophageal xanthoma combined with esophageal cancer. Herein, we present the first case in the literature of a diffuse xanthoma complicated with early esophageal cancer. Moreover, this combination makes the endoscopic diagnosis difficult if it is not in mind.

CASE SUMMARY

A 68-year-old man visited our department with a 2-mo history of epigastric discomfort. He underwent surgery for gastric cancer 6 years ago. Esophagogastroduodenoscopy showed a semi-circumferential irregular yellowish-colored and granular lesion in the esophagus (30-35 cm from the incisors). Using magnifying endoscopy with narrow band imaging, aggregated minute and yellowish-colored spots with tortuous microvessels on the surface were observed, and background coloration was clearly seen in the lesion. As endoscopic biopsy suggested a histologically high-grade dysplasia; the lesion was completely resected en bloc by endoscopic submucosal dissection (ESD). The resected specimen was confirmed to be a squamous cell carcinoma in situ with extensive foamy cells in the superficial mucosal layer. Immunohistochemically, the observed foamy cells were strongly positive for CD68, which is characteristic of xanthoma. The clinical course was favorable, and no recurrence was observed 2 years and 7 mo after ESD.

CONCLUSION

Diffuse xanthoma concurrent with early esophageal cancer is extremely rare. The characteristic endoscopic features may assist endoscopists in diagnosing similar lesions.

Narrow band imaging under less-air condition improves the visibility of superficial esophageal squamous cell carcinoma

BACKGROUND

The current virtual chromoendoscopy equipment cannot completely detect superficial squamous cell carcinoma (SCC) in the esophagus, despite its development in the recent years. Thus, in this study, we aimed to elucidate the appropriate air volume during endoscopic observation to improve the visibility of esophageal SCC.

METHODS

This retrospective study included a total of 101 flat type esophageal SCCs identified between April 2017 and January 2019 at the Department of Gastrointestinal Oncology, Osaka International Cancer Institute. Video images of narrow band imaging (NBI) under both less-air and standard-air conditions were recorded digitally. Videos were evaluated by five endoscopists. Relative visibility between less-air and standard-air conditions of the brownish area, brownish color change of the epithelium, and dilated intrapapillary capillary loop (IPCL) were graded as 5 (definitely better under less-air condition) to 1 (definitely worse under less-air condition), with 3 indicating average visibility (equivalent to standard-air observation).

RESULTS

The mean (standard deviation) visibility score of the brownish area, brownish color change of the epithelium, and dilated IPCLs under less-air condition were 3.94 (0.58), 3.73 (0.57), and 4.13 (0.60), respectively, which were significantly better than that under standard-air condition (p < 0.0001). Esophageal SCC evaluated as ≥ 4 in the mean visibility score of the brownish area, brownish color change of the epithelium, and dilated IPCLs accounted for 50% (51/101 lesions), 34% (34/101 lesions), and 67% (68/101 lesions), respectively.

CONCLUSIONS

The present results suggested that NBI with less air might improve the visibility of flat type esophageal SCC compared with NBI with standard air. Less-air NBI observation may facilitate the detection of flat type esophageal SCC.

TRIAL REGISTRATION

The present study is a non-intervention trial.

Chondromodulin-1 and vascular endothelial growth factor-A expression in esophageal squamous cell carcinoma: accelerator and brake theory for angiogenesis at the early stage of cancer progression

BACKGROUND

Magnifying endoscopy has demonstrated dramatic morphologic changes in the surface microvasculature of superficial esophageal squamous cell carcinoma (ESCC) according to the depth of invasion. We investigated the mechanism of angiogenesis in early-stage ESCC by examining the expression of vascular endothelial growth factor (VEGF)-A and chondromodulin (ChM)-1.

METHODS

Using 41 samples of superficial esophageal cancer (EP and LPM 19 cases, MM or deeper 22 cases) and 7 samples of regenerative squamous epithelium, the expression of VEGF-A and ChM-1 was examined in relation to the histological grade or morphology of the surface microvasculature demonstrated by magnifying endoscopy (types A, B, and C correspond to types A, B1, and B2 and B3 of the magnifying endoscopic classification of the Japan Esophageal Society, respectively). We also investigated the correlation between CD31-positive microvessel density (MVD) and VEGF-A or ChM-1 expression.

RESULTS

In normal squamous epithelium, regenerative squamous epithelium, EP and LPM cancer, and MM or deeper cancer, the positivity rates for VEGF-A and ChM-1 were 0%, 85.7%, 52.6% and 90.9%, respectively, and 48.5%, 71.4%, 73.7% and 23.8%, respectively. The VEGF-A and ChM-1 positivity rates in type B or type C vasculature were 70.0% and 76.2%, respectively, and 75.0% and 19.0%, respectively. The expression of neither VEGF-A nor ChM-1 in cancer cells was correlated with MVD (P = 0.19 and 0.68, respectively), whereas that of VEGF-A in stromal mononuclear cells (SMCs) was significantly correlated with MVD (P = 0.04).

CONCLUSION

Angiogenesis at the early stage of ESCC progression is configured by the balance between accelerator (angiogenic factors from both cancer cells and SMCs) and brake (angiogenic inhibitor) factors.

Color information from linked color imaging is associated with invasion depth and vascular diameter in superficial esophageal squamous cell carcinoma

OBJECTIVES

Accurate diagnosis of invasion depth is important for reliable treatment of esophageal squamous cell carcinoma (ESCC), but it is limited to the muscularis mucosae to slight submucosal invasion (MM/SM1). The diagnostic accuracy of invasion depth is unsatisfactory and remains to be improved. We aimed to investigate the association between the color of the superficial ESCC and invasion depth using linked color imaging (LCI) under light-emitting diode (LED) light sources.

METHODS

Lesions diagnosed as superficial ESCC were observed using white light imaging and then by LCI. The color values were calculated using Commission Internationale de l'Eclariage - L*a*b* color space, and the color difference was calculated according to invasion depth. The vascular diameters and vascular angles of the intrapapillary capillary loops were pathologically analyzed. Their correlation with mucosal color was also investigated by LCI.

RESULTS

In all, 52 lesions from 48 patients were analyzed. On the basis of invasion depth, the color difference between the normal mucosa and the lesion was larger in the MM/SM1 or deeper group than in the epithelium and the lamina propria mucosa (EP/LPM) group using LCI (P = 0.025). The vascular diameter was positively correlated with the b* color value (correlation coefficient = 0.302, P = 0.033).

CONCLUSION

Observation using LCI under LED light sources may improve the endoscopic diagnosis of the invasion depth of superficial ESCC. Further research is needed to validate its usefulness. (UMIN000024615).

Diagnostic efficacy of dual-focus endoscopy with narrow-band imaging using simplified dyad criteria for superficial esophageal squamous cell carcinoma

BACKGROUND

Our previous studies have shown the diagnostic utility of a newly developed dual-focus endoscope with narrow-band imaging (DF-NBI) and simplified dyad criteria for detection of superficial esophageal squamous cell carcinoma (SESCC). This clinical trial aimed to study the diagnostic efficacy of DF-NBI with dyad criteria for detecting SESCC compared to white light imaging (WLI).

METHODS

This was a single-arm prospective comparative trial. We enrolled 170 consecutive high-risk patients for esophageal squamous cell carcinoma. Patients were initially examined with WLI by one independent endoscopist and then the other performed DF-NBI blinded to the WLI diagnosis to avoid a carry-over effect. Lesions showing proliferation and/or various shapes of intrapapillary capillary loops (IPCL) under DF-NBI (i.e., dyad criteria) were endoscopically diagnosed as SESCC including high-grade intraepithelial neoplasia. The primary endpoint was sensitivity of WLI and DF-NBI for detecting SESCC. The secondary endpoints were the diagnostic performance (i.e., specificity and accuracy) and inter/intra-observer concordance of DF-NBI with dyad criteria.

RESULTS

A total 77 SESCCs were detected. The sensitivity of DF-NBI for SESCC was significantly higher than that of WLI (91% vs. 51%, P < 0.001). The specificity and accuracy of WLI and DF-NBI using dyad criteria were 100% vs. 84%, and 86% vs. 86%, respectively. Various shapes and proliferation of IPCL showed the highest value in inter-observer and intra-observer agreements (κ = 0.77 and 0.82, respectively).

CONCLUSION

DF-NBI combined with dyad criteria may be a promising technique with a high sensitivity for diagnosis of SESCC and high inter/intra-observer agreement.

Prediction of the invasion depth of superficial squamous cell carcinoma based on microvessel morphology: magnifying endoscopic classification of the Japan Esophageal Society

Predicting invasion depth of superficial esophageal squamous cell carcinoma is crucial in determining the precise indication for endoscopic resection because the rate of lymph node metastasis increases in proportion to the invasion depth of the carcinoma. Previous studies have shown a close relationship between microvascular patterns observed by Narrow Band Imaging magnifying endoscopy and invasion depth of the superficial carcinoma. Thus, the Japan Esophageal Society (JES) developed a simplified magnifying endoscopic classification for estimating invasion depth of superficial esophageal squamous cell carcinomas. We conducted a prospective study to evaluate the diagnostic values of type B vessels in the pretreatment estimation of invasion depth of superficial esophageal squamous cell carcinomas utilizing JES classification, the criteria of which are based on the degree of irregularity in the microvascular morphology. Type A microvessels corresponded to noncancerous lesions and lack severe irregularity; type B, to cancerous lesions, and exhibit severe irregularity. Type B vessels were subclassified into B1, B2, and B3, diagnostic criteria for T1a-EP or T1a-LPM, T1a-MM or T1b-SM1, and T1b-SM2 tumors, respectively. We enrolled 211 patients with superficial esophageal squamous cell carcinoma. The overall accuracy of type B microvessels in estimating tumor invasion depth was 90.5 %. We propose that the newly developed JES magnifying endoscopic classification is useful in estimating the invasion depth of superficial esophageal squamous cell carcinoma.

Simplified criteria for diagnosing superficial esophageal squamous neoplasms using Narrow Band Imaging magnifying endoscopy

AIM

To simplify the diagnostic criteria for superficial esophageal squamous cell carcinoma (SESCC) on Narrow Band Imaging combined with magnifying endoscopy (NBI-ME).

METHODS

This study was based on the post-hoc analysis of a randomized controlled trial. We performed NBI-ME for 147 patients with present or a history of squamous cell carcinoma in the head and neck, or esophagus between January 2009 and June 2011. Two expert endoscopists detected 89 lesions that were suspicious for SESCC lesions, which had been prospectively evaluated for the following 6 NBI-ME findings in real time: “intervascular background coloration”; “proliferation of intrapapillary capillary loops (IPCL)”; and “dilation”, “tortuosity”, “change in caliber”, and “various shapes (VS)” of IPCLs (i.e., Inoue’s tetrad criteria). The histologic examination of specimens was defined as the gold standard for diagnosis. A stepwise logistic regression analysis was used to identify candidates for the simplified criteria from among the 6 NBI-ME findings for diagnosing SESCCs. We evaluated diagnostic performance of the simplified criteria compared with that of Inoue’s criteria.

RESULTS

Fifty-four lesions (65%) were histologically diagnosed as SESCCs and the others as low-grade intraepithelial neoplasia or inflammation. In the univariate analysis, proliferation, tortuosity, change in caliber, and VS were significantly associated with SESCC (P < 0.01). The combination of VS and proliferation was statistically extracted from the 6 NBI-ME findings by using the stepwise logistic regression model. We defined the combination of VS and proliferation as simplified dyad criteria for SESCC. The areas under the curve of the simplified dyad criteria and Inoue’s tetrad criteria were 0.70 and 0.73, respectively. No significant difference was shown between them. The sensitivity, specificity, and accuracy of diagnosis for SESCC were 77.8%, 57.1%, 69.7% and 51.9%, 80.0%, 62.9% for the simplified dyad criteria and Inoue’s tetrad criteria, respectively.

CONCLUSION

The combination of proliferation and VS may serve as simplified criteria for the diagnosis of SESCC using NBI-ME.

Tolerability of magnifying narrow band imaging endoscopy for esophageal cancer screening

AIM: To compare the tolerability of magnifying narrow band imaging endoscopy for esophageal cancer screening with that of lugol chromoendoscopy.

METHODS: We prospectively enrolled and analyzed 51 patients who were at high risk for esophageal cancer. All patients were divided into two groups: a magnifying narrow band imaging group, and a lugol chromoendoscopy group, for comparison of adverse symptoms. Esophageal cancer screening was performed on withdrawal of the endoscope. The primary endpoint was a score on a visual analogue scale for heartburn after the examination. The secondary endpoints were scale scores for retrosternal pain and dyspnea after the examinations, change in vital signs, total procedure time, and esophageal observation time.

RESULTS: The scores for heartburn and retrosternal pain in the magnifying narrow band imaging group were significantly better than those in the lugol chromoendoscopy group (P = 0.004, 0.024, respectively, ANOVA for repeated measures). The increase in heart rate after the procedure was significantly greater in the lugol chromoendoscopy group. There was no significant difference between the two groups with respect to other vital sign. The total procedure time and esophageal observation time in the magnifying narrow band imaging group were significantly shorter than those in the lugol chromoendoscopy group (450 ± 116 vs 565 ± 174, P = 0.004, 44 ± 26 vs 151 ± 72, P < 0.001, respectively).

CONCLUSION: Magnifying narrow band imaging endoscopy reduced the adverse symptoms compared with lugol chromoendoscopy. Narrow band imaging endoscopy is useful and suitable for esophageal cancer screening periodically.

Significance of background coloration in endoscopic detection of early esophageal squamous cell carcinoma

Endoscopic diagnostics of early squamous cell carcinoma (SCC) in the laryngo-esophageal region have dramatically improved together with development of less invasive endoscopic treatment. It is essential for gastrointestinal endoscopists to detect lesions when they are still endoscopically treatable, especially in this region since surgical approach can still be extremely invasive. Pioneers have found some notable fundamental alterations in early SCC and created several classifications. Inoue [Dig Endosc 2001;13(suppl): 40-41] proposed the intrapapillary capillary (IPCL) classification, which focused on the microvascular change of the mucosal surface. One of the significances of this classification is that it clearly distinguished the lesions that require further pathological evaluation by categorizing the diameter change of the IPCLs. On the other hand, Arima et al. [Esophagus 2005;2:191-197] advocated the alteration of microvessels as well as change of the vascular arrangement in the area. Most recently, the Japan Esophageal Society constructed a new classification uniting these two exemplary classifications as the 'Japanese Classification of Magnifying Endoscopy for Early Squamous Cell Carcinoma'. This classification was intended to be simple and easily applicable in general clinical practice. Brownish color change between the IPCLs has reported to be one of the useful findings in distinguishing early SCC from benign changes such as inflammatory change and low-grade intraepithelial neoplasia. Nevertheless, the exact cause of this phenomenon remains unclear. We recently examined the association of color change with hemoglobin (Hb) in cancer tissue, since NBI exclusively detects the wavelength of Hb in superficial vessels in the gastrointestinal tract. This review article also describes our examination of a distinct finding in esophageal cancer, namely, 'background coloration'.

Endoscopic diagnosis of early neoplasia of the esophagus with narrow band imaging: correlations among background coloration and iodine staining findings

BACKGROUND AND AIM

It was previously reported that high-grade intraepithelial neoplasia of the esophagus turns pink within a few minutes after iodine staining (pink-color sign; PCS); however, iodine staining is uncomfortable. By using narrow band imaging (NBI), color change in the area between the intraepithelial papillary capillary loop (background coloration; BGC) is often observed within the brownish area. The diagnostic usefulness of BGC findings for differentiating high-grade intraepithelial neoplasia from low-grade intraepithelial neoplasia was evaluated.

METHODS

In a prospective observational study from September 2010 to August 2012, 285 patients who were in a high-risk group for esophageal squamous cell carcinoma underwent endoscopic examination. Lesions with both endoscopic findings of dilated intraepithelial papillary capillary loop on NBI and iodine-unstained areas were studied, in which endoscopic biopsy or endoscopic resection was subsequently performed. The esophageal background mucosa was also evaluated on the basis of the iodine staining pattern (uniform type: Group U, scattered type: Group S).

RESULTS

One hundred three esophageal lesions in 87 patients were studied. When BGC was used as the differentiation index, sensitivity was 93.8%, specificity was 88.2%, and accuracy was 91.3%. When PCS was used, sensitivity was 97.9%, specificity was 88.2%, and accuracy was 93.2% (P = 0.79). In Group U (n = 54), BGC had an accuracy of 93.8%, and PCS had an accuracy of 92.3% (P = 1.0). On the other hand, in Group S (n = 33), BGC had an accuracy of 86.8%, while PCS had an accuracy of 94.7% (P = 0.27).

CONCLUSIONS

Diagnosis using BGC on NBI may substitute for diagnosis based on PCS in many patients.

Update on narrow band imaging in disorders of the upper gastrointestinal tract

With the ever-increasing concern regarding morbidity and mortality associated with diseases of the gastrointestinal tract, the importance of an effective and efficient diagnostic tool cannot be overstated. The standard of care currently is an examination using conventional white light endoscopy. This approach may occasionally overlook areas exhibiting a premalignant change. Numerous image-enhanced modalities have been recently introduced. Narrow band imaging (NBI) appears to be the most prominent of these and perhaps the most commonly used. Thepresent review will focus on some of the newer studies on NBI and its utility in the diagnosis of malignant, pre-malignant and chronic inflammatory conditions of the upper gastrointestinal tract.

Background coloration of squamous epithelium in esophago-pharyngeal squamous cell carcinoma: what causes the color change?

OBJECTIVES

This study aims to clarify the cause of background coloration in the epithelia between each dilated intra papillary capillary loop in esophago-pharyngeal squamous cell carcinoma.

DESIGN

This is a single center retrospective study including 124 patients with 160 lesions who underwent esophagogastroduodenoscopy in Nagasaki University Hospital from September 2007 to March 2012; a detailed comparison between endoscopic images and pathology was performed. Immunohistological assessment using anti-human hemoglobin antibody (anti-Hb Ab) was performed to verify the presence of hemoglobin (Hb) component in the cancer cells. Real-time polymerase chain reaction (RT-PCR) and in situ hybridization (ISH) on Hb-β mRNA were performed to assess the production of Hb component within the cancer cells.

RESULTS

A strong positivity for anti-Hb Ab was observed in the squamous cell carcinoma area, whereas non-cancerous mucosa showed no immunopositivity for Hb. The concordance rate between anti-Hb Ab immunoreactivity and the presence of BC was as high as 80.9%. The amount of Hb-β mRNA expression was three times higher in cancer tissues compared with the surrounding non-cancerous mucosa. ISH images showed that the expression exclusively occurred in cancer cells, indicating that Hb is probably produced within cancer cells.

CONCLUSIONS

The background coloration observed is partly due to an extravascular component of Hb. RT-PCR and ISH analyses indicate that Hb is produced within cancer cells.

Perspectives on narrow-band imaging endoscopy for superficial squamous neoplasms of the orohypopharynx and esophagus

BACKGROUND AND AIM

Narrow-band imaging (NBI) is widely available and over the last decade has been applied as a detection and characterization technique for superficial neoplasms of the aerodigestive tract. The aims of the present study were to systematically review clinical trials of NBI endoscopy and to investigate an upgraded NBI system using a novel endoscope for superficial squamous neoplasms in the orohypopharynx and esophagus.

METHODS

Studies on the diagnostic use of NBI endoscopy for superficial squamous neoplasms in the orohypopharynx and esophagus were retrieved from MEDLINE and PubMed and reviewed. An upgraded NBI system using a novel endoscope was investigated with our clinical cases.

RESULTS

In many clinical trials, NBI endoscopy with or without magnification had high diagnostic value for superficial squamousneoplasms in the orohypopharynx and esophagus. An upgraded NBI system can produce a significantly brighter endoscopic view than conventional endoscopes with high-quality magnified images that could be used to diagnose superficial squamous neoplasms.

CONCLUSIONS

NBI endoscopy with or without magnification has diagnostic utility for superficial squamous neoplasms in the orohypopharynx and esophagus. The upgraded NBI endoscopic system is expected to facilitate the use of NBI and magnifying endoscopic diagnosis.