Squamous cell carcinoma in situ at oropharyngeal and hypopharyngeal mucosal sites

Narrow band imaging versus conventional white light colonoscopy for the detection of colorectal polyps

BACKGROUND

It has been suggested that narrow band imaging colonoscopy (NBI) might be better for detection of colorectal polyps than white light colonoscopy (WLC).

OBJECTIVES

To compare standard or high definition white light colonoscopy with narrow band imaging colonoscopy for detection of colorectal polyps.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, and EMBASE to August 2011. We scanned bibliographies of relevant publications and wrote to experts for additional trials.

SELECTION CRITERIA

Two authors (NA and GB) independently applied the inclusion criteria and extracted the data to all potential studies without blinding.

DATA COLLECTION AND ANALYSIS

Authors extracted data independently. Trials with adequate randomisation, allocation concealment, and complete outcome data reporting, as well as without selective outcome reporting or other bias were classified as having a lowest risk of bias. Random-effects and fixed-effect meta-analyses were conducted.

MAIN RESULTS

We identified 11 randomised trials comparing WLC with NBI for detection of colorectal polyps. In total eight randomised trials with 3673 participants provided data for our analyses. There was no statistically significant difference between WLC (standard definition and high definition pooled) and NBI for the detection of patients with colorectal polyps (6 trials, n = 2832, RR 0.97, 95% CI 0.91 to 1.04), patients with colorectal adenomas (8 trials, n = 3673, RR 0.94, 95% CI 0.87 to 1.02), or patients with colorectal hyperplastic polyps (2 trials, n = 645, RR 0.87, 95% CI 0.76 to 1.00). Number of patients with at least one colorectal adenoma was not significantly different between WLC and NBI group irrespective of adenoma size (< 5 mm:RR 0.95, 95% CI 0.84 to 1.08, I(2) = 56%; 6 to 9 mm: RR 1.06, 95% CI 0.81 to 1.39, I(2) = 0%; ≥ 10 mm: RR 1.06, 95% CI 0.77 to 1.45, I(2) = 0%). Number of patients with at least one colorectal polyp, or colorectal adenoma was significantly lower in the standard definition WLC group compared to NBI group in fixed-effect meta-analysis (RR 0.87, 95% CI 0.78 to 0.97, I(2) = 78%; RR 0.87, 95% CI 0.77 to 0.99, I(2) = 0%, respectively), but not significantly different in random-effects meta-analysis (RR 0.86, 95% CI 0.68 to 1.10, I(2) = 78%). There was no statistically significant difference between high definition WLC and NBI in the number of patiens with at least one colorectal polyp or colorectal adenoma (RR 1.10, 95% CI 0.95 to 1.28; RR 0.87, 95% CI 0.77 to 0.99, I(2) = 0%, respectively).

AUTHORS' CONCLUSIONS

We could not find convincing evidence that NBI is significantly better than high definition WLC for the detection of patients with colorectal polyps, or colorectal adenomas. We found evidence that NBI might be better than standard definition WLC and equal to high definition WLC for detection the patients with colorectal polyps, or colorectal adenomas.

Diagnostic utility of narrow-band imaging endoscopy for pharyngeal superficial carcinoma

AIM: To investigate the endoscopic features of pharyngeal superficial carcinoma and evaluate the utility of narrow-band imaging (NBI) for this disease.

METHODS: In the present prospective study, 335 patients underwent conventional white light (CWL) endoscopy and non-magnified/magnified NBI endoscopy, followed by an endoscopic biopsy, for 445 superficial lesions in the oropharynx and hypopharynx. The macroscopic appearance of superficial lesions was categorized as either elevated (< 5 mm in height), flat, or depressed (not ulcerous). Superficial carcinoma (SC) was defined as a superficial lesion showing high-grade dysplasia or squamous cell carcinoma on histology. The color, delineation, and macroscopic appearances of the lesions were evaluated by CWL endoscopy. The ratio of the brownish area/intervascular brownish epithelium (IBE), as well as microvascular proliferation, dilation, and irregularities, was determined by non-magnified/magnified NBI endoscopy. An experienced pathologist who was unaware of the endoscopic findings made the histological diagnoses. By comparing endoscopic findings with histology, we determined the endoscopic features of SC and evaluated the diagnostic utility of NBI.

RESULTS: The 445 lesions were divided histologically into two groups: a non-SC group, including non-neoplasia and low-grade dysplasia cases, and an SC group. Of the 445 lesions examined, 333 were classified as non-SC and 112 were classified as SC. There were no significant differences in age, gender, or the location of the lesions between the patients in the two groups. The mean diameter of the SC lesions was significantly greater than that of non-SC lesions (11.0 ± 7.6 mm vs 4.6 ± 3.6 mm, respectively, P < 0.001). Comparisons of CWL endoscopy findings for SC and non-SC lesions by univariate analysis revealed that the incidence of redness (72% vs 41%, respectively, P < 0.001) and a flat or depressed type of lesion (58% vs 44%, respectively, P = 0.013) was significantly higher in the SC group. Using non-magnified NBI endoscopy, the incidence of a brownish area was significantly higher for SC lesions (79% vs 57%, respectively, P < 0.001). On magnified NBI endoscopy, the incidence of IBE (68% vs 33%, P < 0.001) and microvascular proliferation (82% vs 51%, P < 0.001), dilation (90% vs 76%, P = 0.002), and irregularity (82% vs 31%, P < 0.001) was also significantly higher for the SC compared with the non-SC lesions. Multivariate analysis revealed that the incidence of redness (P = 0.022) on CWL endoscopy and IBE (P < 0.001) and microvascular irregularities (P < 0.001) on magnified NBI endoscopy was significantly higher in SC than non-SC lesions. Redness alone exhibited significantly higher sensitivity and significantly lower specificity for the diagnosis of SC compared with redness plus IBE and microvascular irregularities (72% vs 52%, P = 0.002; and 59% vs 92%, P < 0.001, respectively). The accuracy of redness plus IBE and irregularities for the diagnosis of SC was significantly greater than using redness alone (82% vs 62%, respectively, P < 0.001).

CONCLUSION: Redness, IBE, and microvascular irregularities appear to be closely related to SC lesions. Magnified NBI endoscopy may increase the diagnostic accuracy of CWL endoscopy for SC.

Detection of mucosal recurrent nasopharyngeal carcinomas after radiotherapy with narrow-band imaging endoscopy

PURPOSE

This study evaluated the feasibility of screening mucosal recurrent nasopharyngeal carcinoma with narrow-band imaging (NBI) endoscopy.

METHODS AND MATERIALS

One hundred and six patients were enrolled. All patients underwent conventional white-light (WL) endoscopic examination of the nasopharynx followed by NBI endoscopy. Biopsies were performed if recurrence was suspected.

RESULTS

We identified 32 suspected lesions by endoscopy in WL and/or NBI mode. Scattered brown spots (BS) were identified in 22 patients, and 4 of the 22 who had negative MRI findings were histopathologically confirmed to be neoplasias that were successfully removed via endoscopy. A comparison of the visualization in NBI closer view corresponded to histopathological findings in 22 BS, and the prevalence rates of neoplasias in tail signs, round signs, and irregularities signs were 0% (0/6), 0% (0/7), and 44.4% (4/9), respectively (p = 0.048). The sensitivity, specificity, and diagnostic capability were 37.5%, 92.9% and 0.652 for WL, 87.5%, 74.5% and 0.810 for NBI, and 87.5%, 87.8%, and 0.876 for NBI closer view, respectively. NBI closer view was effective in increasing specificity compared with NBI alone (87.8% vs. 74.5%, p < 0.05), and in increasing sensitivity and diagnostic capability compared to WL alone (87.5% vs. 37.5%, p < 0.05; 0.876 vs. 0.652, p = 0.0001).

CONCLUSIONS

Although NBI in endoscopy can improve sensitivity of mucosal recurrent nasopharyngeal neoplasias, false-positive (nonneoplasia BS) results may be obtained in areas with nonspecific inflammatory changes due to postradiation effects. NBI closer view not only can offer a timely, convenient, and highly reliable assessment of mucosal recurrent nasopharyngeal carcinoma, it can also make endoscopic removal possible.

Use of endoscopy with narrow-band imaging system in evaluating oral leukoplakia

BACKGROUND

The purpose of this study was to analyze the relationship between clinical features of oral leukoplakia using endoscopy with broadband white light, narrow-band imaging (NBI) illumination, and histopathology, and to discuss the clinical relevance of the NBI system.

METHODS

Clinicopathologic data of patients receiving biopsy or excision after endoscopic examination for leukoplakia from April 2009 to December 2010 were reviewed and analyzed statistically.

RESULTS

A total 154 patients, 130 men and 24 women (average age, 52.60 ± 10.86 years) were enrolled. The correlation between intraepithelium papillary capillary loop (IPCL) classification and stepwise increased severity of pathology (Pearson's r = .88, R(2) = 0.78) was significantly better than that of broadband white light images (p < .001).

CONCLUSIONS

Flexible endoscopy can enhance detailed inspection of oral cavity mucosa and can be a powerful tool for examining oral leukoplakia. The IPCL patterns shown by NBI system can be helpful in detecting oral leukoplakia with higher grade dysplasia or invasive carcinoma.

Narrow-band imaging without magnification for detecting early esophageal squamous cell carcinoma

AIM: To compare narrow-band imaging (NBI) without image magnification, and chromoendoscopy with Lugol’s solution for detecting high-grade dysplasia and intramucosal esophageal squamous cell carcinoma (SCC) in patients with head and neck cancer.

METHODS: This was a prospective observational study of 129 patients with primary head and neck tumors consecutively referred to the Gastrointestinal Endoscopy Unit of Hospital das Clínicas, São Paulo University Medical School, Brazil, between August 2006 and February 2007. Conventional examinations with NBI and Lugol chromoendoscopy were consecutively performed, and the discovered lesions were mapped, recorded and sent for biopsy. The results of the three methods were compared regarding sensitivity, specificity, accuracy, positive predictive value, negative predictive value, positive likelihood value and negative likelihood value.

RESULTS: Of the 129 patients, nine (7%) were diagnosed with SCC, 5 of which were in situ and 4 which were intramucosal. All carcinomas were detected through NBI and Lugol chromoendoscopy. Only 4 lesions were diagnosed through conventional examination, all of which were larger than 10 mm.

CONCLUSION: NBI technology with optical filters has high sensitivity and high negative predictive value for detecting superficial esophageal SCC, and produces results comparable to those obtained with 2.5% Lugol chromoendoscopy.

Long-term outcome of transoral organ-preserving pharyngeal endoscopic resection for superficial pharyngeal cancer

BACKGROUND

Early detection of pharyngeal cancer has been difficult. We reported that narrow-band imaging (NBI) endoscopy can detect superficial pharyngeal cancer, and these lesions can be treated endoscopically.

OBJECTIVE

To assess the safety and long-term efficacy of transoral organ-preserving pharyngeal endoscopic resection (TOPER) for superficial pharyngeal cancer.

DESIGN AND SETTING

Retrospective 2-center cohort study.

PATIENTS

The study included 104 consecutive patients with superficial pharyngeal cancer.

INTERVENTION

TOPER with the patients under general anesthesia.

MAIN OUTCOME MEASUREMENTS

Safety of the procedure, long-term survival, clinical outcome.

RESULTS

A total of 148 consecutive lesions were resected in 104 patients. There was no severe adverse event. Temporary tracheostomy was required in 17 patients (16%) to prevent airway obstruction. The median fasting period and hospital stay after TOPER were 2 days (range 1-20 days) and 8 days (range 3-58 days), respectively. Ninety-six patients (92%) had no local recurrence or distant metastases. Local recurrence at the primary site developed in 6 patients, but all were resolved by repeat TOPER. With a median follow-up period of 43 months (range 3-96 months), the overall survival rate at 5 years was 71% (95% CI, 59-82). Cause-specific survival rate at 5 years was 97% (95% CI, 93-100). The cumulative development rate of multiple cancers in pharyngeal mucosal sites at 5 years was 22% (95% CI, 12-33). The pharynx was preserved in all patients, and they experienced no loss of function.

LIMITATION

Retrospective design.

CONCLUSIONS

Peroral endoscopic resection of superficial pharyngeal cancer is a feasible and effective treatment with curative intent.

Differences of image enhancement in image-enhanced endoscopy: narrow band imaging versus flexible spectral imaging color enhancement

BACKGROUND

Narrow band imaging (NBI) can emphasize images of the surface microvasculature of lesions, because the central wavelengths of the NBI filter are 415 and 540 nm and these wavelengths are well absorbed by hemoglobin. Flexible spectral imaging color enhancement (FICE) increases the contrast in depictions of mucosal lesions. However, quantitative evaluation of the image enhancement shown by NBI and FICE has not been reported. The aim of this study was to measure and compare the degrees of image enhancement in NBI and FICE.

METHODS

We compared the visibility of human blood diluted with distilled water between that shown by white-light imaging (WLI) and that shown by NBI or FICE. One milliliter of human blood was plated onto a 12-well transparent plastic plate to set up doubling dilutions, from 1/2 to 1/2(23). High-definition endoscopes were used for each imaging method. A total of 11 endoscopists independently evaluated the visibility of the diluted blood. The median dilution was defined as the limit of visibility in each image.

RESULTS

NBI enabled clearer visualization of the presence of blood compared with conventional WLI. NBI recognized blood contamination up to a 1/2(14) dilution, whereas conventional WLI recognized blood contamination up to a 1/2(11) dilution. In contrast, FICE did not improve the visualization of diluted blood and recognized blood contamination up to a 1/2(10) dilution.

CONCLUSIONS

NBI more effectively enhanced images of diluted blood compared to conventional WLI, while FICE did not improve the visualization of the diluted blood. These data suggest the usefulness of NBI for the early detection of gastrointestinal neoplasia, which is accompanied by abundant neovascularization.

Alcohol and aldehyde dehydrogenase polymorphisms and a new strategy for prevention and screening for cancer in the upper aerodigestive tract in East Asians

The ethanol in alcoholic beverages and the acetaldehyde associated with alcohol consumption are Group 1 human carcinogens (WHO, International Agency for Research on Cancer). The combination of alcohol consumption, tobacco smoking, the inactive heterozygous aldehyde dehydrogenase-2 genotype (ALDH2*1/*2) and the less-active homozygous alcohol dehydrogenase-1B genotype (ADH1B*1/*1) increases the risk of squamous cell carcinoma (SCC) in the upper aerodigestive tract (UADT) in a multiplicative fashion in East Asians. In addition to being exposed to locally high levels of ethanol, the UADT is exposed to a very high concentration of acetaldehyde from a variety of sources, including that as an ingredient of alcoholic beverages per se and that found in tobacco smoke; acetaldehyde is also produced by salivary microorganisms and mucosal enzymes and is present as blood acetaldehyde. The inefficient degradation of acetaldehyde by weakly expressed ALDH2 in the UADT may be cri! tical to the local accumulation of acetaldehyde, especially in ALDH2*1/*2 carriers. ADH1B*1/*1 carriers tend to experience less intense alcohol flushing and are highly susceptible to heavy drinking and alcoholism. Heavy drinking by persons with the less-active ADH1B*1/*1 leads to longer exposure of the UADT to salivary ethanol and acetaldehyde. The ALDH2*1/*2 genotype is a very strong predictor of synchronous and metachronous multiple SCCs in the UADT. High red cell mean corpuscular volume (MCV), esophageal dysplasia, and melanosis in the UADT, all of which are frequently found in ALDH2*1/*2 drinkers, are useful for identifying high-risk individuals. We invented a simple flushing questionnaire that enables prediction of the ALDH2 phenotype. New health appraisal models that include ALDH2 genotype, the simple flushing questionnaire, or MCV are powerful tools for devising a new strategy for prevention and screening for UADT cancer in East Asians.

Role of narrow band imaging for diagnosis of early-stage esophagogastric cancer: current consensus of experienced endoscopists in Asia-Pacific region

In Asian countries, squamous cell carcinoma is the most common type of esophageal cancer, and the incidence of gastric cancer remains have plateaued. To synthesize current information and to illustrate its clinical benefit of narrow band imaging (NBI) for diagnosis of superficial esophageal squamous carcinoma (SESCC) and early gastric cancer (EGC), a consensus conference was held by a panel of nine experts from Asian-Pacific countries. The expert's agreement suggested importance of interpretation of both vascular architecture and surface structure of the lesions and proper processor settings for endoscopic images. Zoom endoscopy was not regarded as absolutely necessary for detection of SESCC, but magnifying observation provided valuable information for characterization of detected lesions in the esophagus and the stomach. In general, NBI is useful for detection and characterization of SESCC, whereas it is beneficial mainly for characterization of EGC. Chromoendoscopy was found to be still worthwhile in certain situations, such as determination of the extent of SESCC by Lugol's staining, or detection and delineation of EGC by indigo carmine. NBI could replace chromoendoscopy in routine examination because it is easy to use and adds much information to conventional WLI, but it cannot eliminate chromoendoscopy when we make a final diagnosis for treatment decision-making. Consequently, the benefit of NBI or magnifying NBI is specific for the organ and the purpose of the examination, thus optimum indication and usage should be understood for maximum clinical benefit.

Lugol-voiding lesions are an important risk factor for a second primary squamous cell carcinoma in patients with esosphageal cancer or head and neck cancer

OBJECTIVES

Lugol-voiding lesions (LVLs), detected by chromoendoscopy using iodine dye in patients with esophageal squamous cell carcinoma (EC) or head and neck squamous cell carcinoma (HNC), are associated with a second primary carcinoma in the other organ. We undertook a cross-sectional and retrospective cohort study to assess the risk for second primary carcinomas according to the severity of LVLs, on the basis of their number and size.

METHODS

A total of 1,060 patients with only EC, only HNC, or both EC and HNC (EC+HNC) underwent esophageal endoscopic examination between January 1994 and January 2010. The patients were classified according to the number of LVLs in an endoscopic visual field and the size of the largest LVLs. Factors associated with the second primary EC or HNC were analyzed.

RESULTS

Univariate analysis showed that a larger number and size of LVLs increased the risk for synchronous and early metachronous second primary cancer (P value for trend <0.0001). Multivariate analysis showed that a number of LVLs ≥20 (EC+HNC vs. only HNC, odds ratio (OR)=15.7; EC+HNC vs. only EC, 3.5) and a size ≥10 mm (EC+HNC vs. only HNC, OR=3.1; EC+HNC vs. only EC, 3.2) were independent risk factors for synchronous and early metachronous second primary cancer. A larger number of LVLs was a risk factor for metachronous EC and HNC, and a size ≥10 mm was a risk factor for late metachronous EC.

CONCLUSIONS

The severity of LVLs in patients with HNC or EC closely correlated with a second primary carcinoma in the other organ. Patients with LVLs must be followed closely for development of a second primary carcinoma.

Nasopharyngeal carcinoma detected by narrow-band imaging endoscopy

The aim of the study was to investigate the novel endoscopic findings in nasopharyngeal carcinoma (NPC) under narrow-band imaging (NBI) and to determine the reliability of screening NPC by NBI. A total of 79 adults underwent nasopharyngeal biopsy. We proposed five distinctly different findings that need to be examined by NBI: Type I: brownish spots, Type II: irregular microvascular pattern (IMVP), Type III: light crests, Type IV: side-difference, Type V: presence of either IMVP or side-difference, of which last three (Type III-V) were a new concept. The results of NPC diagnosis by detecting NBI Type V pattern, the false positive, false negative, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 6.7%, 2.9%, 97.1%, 93.3%, 91.7%, 97.7%, and 94.9%, respectively. On the other hand, there was a higher prevalence of Type I and IV patterns in T1 category NPC. The nasopharyngeal endoscopy coupled with NBI was able to provide a rapid, convenient, and highly reliable screening for high-risk populations.

Use of narrow band imaging in evaluation of possible nasopharyngeal carcinoma

Background

This study was designed to evaluate the narrow band imaging (NBI) system for its ability to differentiate between malignant neoplasm and benign neoplasm by real-time image during nasopharyngoscopy, the quality of the visualization, and the limitation of the NBI in nasopharyngeal lesions.

Methods

Between June 2009 and May 2010, 63 patients who had a suspected nasopharyngeal tumor via nasopharyngoscopy at Taipei Veterans General Hospital, Taiwan, were included in this study. All of the patients received nasopharyngoscopy with conventional view and NBI view and nasopharyngeal biopsy. The patients were divided into two groups depending on the pathological results: nasopharyngeal carcinoma (NPC) and lymphoid hyperplasia/chronic inflammation (LH).

Results

Forty-one patients were in the NPC group and 22 patients were in the LH group. The pattern of the NBI view showed regular cobblestone in the LH group, except for one patient. The pattern of the NBI view showed an irregular engorged vascular pattern and/or microvascular proliferative pattern in 32 of 41 NPC patients (78.0%). The sensitivity, specificity, positive predictive value, and negative predictive value of NBI in nasopharynx (NP) were 78.0, 95.5, 97.0, and 70.0%, respectively, in NP neoplasm.

Conclusion

NBI could be helpful in differentiating benign and malignant neoplasm in the NP region. Using NBI in NP regions had some limitations, including bleeding and mucus coating.

Diagnosis of the extent of advanced oropharyngeal and hypopharyngeal cancers by narrow band imaging with magnifying endoscopy

OBJECTIVES/HYPOTHESIS

Narrow band imaging combined with magnifying endoscopy (NBI-ME) is useful for the detection of superficial cancer in the oropharynx, hypopharynx, and esophagus. We used NBI-ME to evaluate the frequency of superficial cancer spread (SCS) contiguous with advanced oropharyngeal and hypopharyngeal cancers and esophageal cancers.

STUDY DESIGN

Retrospective.

METHODS

We retrospectively studied 45 patients with oropharyngeal and hypopharyngeal cancer and 44 with esophageal cancer who underwent NBI-ME from October 2006 through April 2009. The following variables were evaluated: 1) the frequency of SCS contiguous with advanced oropharyngeal and hypopharyngeal cancer and esophageal cancer, and 2) the influence of SCS contiguous with advanced oropharyngeal and hypopharyngeal cancer on clinical T category and clinical stage.

RESULTS

SCS contiguous with the primary tumor was found in 49% (22/45) of the patients with advanced oropharyngeal and hypopharyngeal cancer and in 52% (23/44) of those with advanced esophageal cancer. When SCS contiguous with the primary tumor was included in the evaluation of tumor size in advanced oropharyngeal and hypopharyngeal cancer, the clinical T category and clinical stage were revised in 20% (9/45) and 4% (2/45) of patients, respectively; SCS was ≤ 2 cm in 64% of cases (14/22) and between >2 cm and ≤ 4 cm in 36% (8/22).

CONCLUSIONS

NBI-ME should be included in the pretreatment diagnostic work-up to evaluate lesion extent and decide optimal surgical margins and radiation fields in patients with advanced oropharyngeal and hypopharyngeal cancer.

Microvascular irregularities are associated with composition of squamous epithelial lesions and correlate with subepithelial invasion of superficial-type pharyngeal squamous cell carcinoma

AIMS

Superficial squamous epithelial lesions of the pharynx are increasingly recognized by architectural changes in the intraepithelial papillary capillary loop (IPCL) assessed by narrow-band imaging (NBI). The aim was to explore the histology of squamous epithelial precursor lesions and superficial-type pharyngeal squamous cell carcinoma (STPSCC), including squamous cell carcinoma (SCC) in situ and early invasive SCC, by focusing on microvascular irregularities to investigate the composition of those lesions and to explore the pathological characteristics of STPSCCs.

METHODS AND RESULTS

Several pathological factors including thickness of intraepithelial squamous cell carcinoma (IESCC) and tumour thickness and microvascular density (MVD) were examined in 104 STPSCCs from 69 patients. The results show that architectural change of IPCL was recognized in precursor lesions in parallel with architectural disturbance and cytological atypia for criteria of diagnosing dysplasia. In 104 STPSCCs, the MVD of IESCC was correlated with the thickness of IESCC (P = 0.0115). Moreover, invasive SCC showed significantly higher MVD of IESCC (P = 0.0078) and there was significant correlation between the thickness of IESCC and subepithelial invasion (P < 0.0001).

CONCLUSIONS

Microvascular irregularities are an important pathological factor in carcinogenesis and early invasiveness of SCC of the pharynx.

Oral premalignant lesions: from the pathological viewpoint

Under the widely used World Health Organization (WHO) classification for the pathological diagnosis of oral premalignant lesions, dysplasia, which is graded as mild, moderate or severe, and carcinoma in situ (CIS), which is a non-invasive carcinoma, are classified as precursor lesions of oral squamous cell carcinoma. Since the first edition (Wahi et al. International histological classification of tumours no. 4, WHO, Geneva, 1971), the criterion for CIS--that all epithelial layers are replaced by atypical cells--has remained unchanged. However, this dysplasia-carcinoma sequence theory was introduced from the viewpoint of pathological changes in the uterine cervix: in contrast, almost all premalignant lesions and CIS of the oral mucosa show superficial maturation and differentiation. Based on this recognition, the squamous intraepithelial neoplasia (SIN) classification and Ljubljana classification were included in WHO's latest edition published in 2005. Although the WHO classification is commonly used in Japan, recent developments in oral oncology have promoted modifications of the classification used in this country. In 2005, the Working Group of the Japan Society for Oral Tumours advocated iodine staining and proposed a modified SIN system, and in 2007, the Working Committee of the Japanese Society for Oral Pathology (JSOP) reported a new CIS (JSOP) definition that included differentiated-type CIS. In 2010, based on these studies, a new entity--oral intraepithelial neoplasia (OIN)--was included in the first edition of General Rules for Clinical and Pathological Studies on Oral Cancer. In this review, we focus on the OIN/CIS (JSOP) new classification of premalignant lesions in oral mucosa, which further advances the concept of SIN.

Autofluorescence imaging and magnification endoscopy

It is well known that angiogenesis is critical in the transition from premalignant to malignant lesions. Consequently, early detection and diagnosis based on morphological changes to the microvessels are crucial. In the last few years, new imaging techniques which utilize the properties of light-tissue interaction have been developed to increase early diagnosis of gastrointestinal (GI) tract neoplasia. We analyzed several “red-flag” endoscopic techniques used to enhance visualization of the vascular pattern of preneoplastic and neoplastic lesions (e.g. trimodal imaging including autofluorescence imaging, magnifying endoscopy and narrow band imaging). These new endoscopic techniques provide better visualization of mucosal microsurface structure and microvascular architecture and may enhance the diagnosis and characterization of mucosal lesions in the GI tract. In the near future, it is expected that trimodal imaging endoscopy will be practiced as a standard endoscopy technique as it is quick, safe and accurate for making a precise diagnosis of gastrointestinal pathology, with an emphasis on the diagnosis of early GI tract cancers. Further large-scale randomized controlled trials comparing these modalities in different patient subpopulations are warranted before their endorsement in the routine practice of GI endoscopy.

Endoscopic diagnosis of laryngeal cancer and precancerous lesions by narrow band imaging

Objective:

To investigate the characteristics of the laryngeal mucosal microvascular network in suspected laryngeal cancer patients, using narrow band imaging, and to evaluate the value of narrow band imaging endoscopy in the early diagnosis of laryngeal precancerous and cancerous lesions.

Patients and methods:

Eighty-five consecutive patients with suspected precancerous or cancerous laryngeal lesions were enrolled in the study. Endoscopic narrow band imaging findings were classified into five types (I to V) according to the features of the mucosal intraepithelial papillary capillary loops assessed.

Results:

A total of 104 lesions (45 malignancies and 59 nonmalignancies) was detected under white light and narrow band imaging modes. The sensitivity and specificity of narrow band imaging in detecting malignant lesions were 88.9 and 93.2 per cent, respectively. The intraepithelial papillary capillary loop classification, as determined by narrow band imaging, was closely associated with the laryngeal lesions' histological findings. Type I to IV lesions were considered nonmalignant and type V lesions malignant. For type Va lesions, the sensitivity and specificity of narrow band imaging in detecting severe dysplasia or carcinoma in situ were 100 and 79.5 per cent, respectively. In patients with type Vb and Vc lesions, the sensitivity and specificity of narrow band imaging in detecting invasive carcinoma were 83.8 and 100 per cent, respectively.

Conclusion:

Narrow band imaging is a promising approach enabling in vivo differentiation of nonmalignant from malignant laryngeal lesions by evaluating the morphology of mucosal capillaries. These results suggest endoscopic narrow band imaging may be useful in the early detection of laryngeal cancer and precancerous lesions.

Early detection in head and neck cancer - current state and future perspectives

Survival and quality of life in head and neck cancer are directly linked to the size of the primary tumor at first detection. In order to achieve substantial gain at these issues, both, primary prevention and secondary prevention, which is early detection of malignant lesions at a small size, have to be improved. So far, there is not only a lack in the necessary infrastructure not only in Germany, but rather worldwide, but additionally the techniques developed so far for early detection have a significance and specificity too low as to warrant safe implementation for screening programs. However, the advancements recently achieved in endoscopy and in quantitative analysis of hypocellular specimens open new perspectives for secondary prevention. Chromoendoscopy and narrow band imaging (NBI) pinpoint suspicious lesions more easily, confocal endomicroscopy and optical coherence tomography obtain optical sections through those lesions, and hyperspectral imaging classifies lesions according to characteristic spectral signatures. These techniques therefore obtain optical biopsies. Once a "bloody" biopsy has been taken, the plethora of parameters that can be quantified objectively has been increased and could be the basis for an objective and quantitative classification of epithelial lesions (multiparametric cytometry, quantitative histology). Finally, cytomics and proteomics approaches, and lab-on-the-chip technology might help to identify patients at high-risk. Sensitivity and specificity of these approaches have to be validated, yet, and some techniques have to be adapted for the specific conditions for early detection of head and neck cancer. On this background it has to be stated that it is still a long way to go until a population based screening for head and neck cancer is available. The recent results of screening for cancer of the prostate and breast highlight the difficulties implemented in such a task.

Observation of the esophagus, pharynx and lingual root by gastrointestinal endoscopy with a percutaneous retrograde approach

AIM: To evaluate the efficacy of retrograde observation of the esophagus, pharynx, larynx and lingual root.

METHODS: With the beagle dog under anesthesia, the anterior wall of the stomach was fixed on the abdominal wall in a similar way to percutaneous endoscopic gastrostomy. The gastrointestinal scope was inserted via a 12 mm laparoscopic port for subsequent retrograde observation from stomach to the oral cavity.

RESULTS: With this technique, direct observation of gastric cardia was possible without restriction. The cervical esophagus was dilated well, also allowing clear observation of the hypopharyngo-esophageal junction. If the tongue was manually pulled out forward, observation of the lingual root was possible.

CONCLUSION: This procedure is easy and effective for pre-treatment evaluation of the feasibility of endoscopic resection in cases of superficial carcinoma of head and neck.

Prospective evaluation of narrow-band imaging endoscopy for screening of esophageal squamous mucosal high-grade neoplasia in experienced and less experienced endoscopists

Narrow-band imaging (NBI) is a novel, noninvasive optical technique that uses reflected light to visualize the organ surface. However, few prospective studies that examine the efficacy of NBI screening for esophageal cancer have been reported. To compare the diagnostic yield of NBI endoscopy for screening of squamous mucosal high-grade neoplasia of the esophagus between experienced and less experienced endoscopists. Patients with a history of esophageal neoplasia or head and neck cancer received NBI endoscopic screening for esophageal neoplasia followed by chromoendoscopy using iodine staining. Biopsy specimens were taken from iodine-unstained lesions and the histological results of mucosal high-grade neoplasias served as the reference standard. The primary outcome was the sensitivity of NBI for detecting new lesions. The secondary outcome was the positive predictive value of NBI and the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of NBI in a per lesion basis. A total of 350 patients (170 by experienced endoscopists and 180 by less experienced endoscopists) underwent endoscopic examination. A total of 42 new mucosal high-grade neoplastic lesions (25 in the experienced endoscopist group and 17 in the less experienced endoscopist group) were detected. In the per-lesion-based analysis, the sensitivity was significantly higher in the experienced endoscopist group (100%; 25/25) compared with the less experienced endoscopist group (53%; 9/17) (P < 0.001). The positive predictive value of NBI was higher in the experienced endoscopist group than in the less experienced endoscopist group (45%, 25/55 vs. 35%, 9/26), although the difference was not significant (P = 0.50). The sensitivity of NBI in the less experienced endoscopist group was 43% in the former half of patients, and increased to 60% in the latter half of patients. In the per-patient-based analysis, the sensitivity of NBI was significantly higher in the experienced endoscopist group (100%) than in the less experienced endoscopist group (100 vs. 69%, respectively; P = 0.04). The positive predictive values of the experienced endoscopist group and the less experienced endoscopist group were similar, and were 48 and 47%, respectively. In conclusion, compared with the gold standard of chromoendoscopy with iodine staining, the sensitivity of NBI for screening of mucosal high-grade neoplasia was 100% with the experienced endoscopists but was low with the less experienced endoscopists. Electronic chromoendoscopy with NBI is a promising screening tool in these high-risk patients with esophageal mucosal high-grade neoplasia, particularly when performed by endoscopists with experience of using NBI.

Significance of each narrow-band imaging finding in diagnosing squamous mucosal high-grade neoplasia of the esophagus

BACKGROUND AND AIM

Although narrow-band imaging (NBI) is used increasingly in clinical situations, the significance of each NBI finding has not been investigated. The primary endpoint of the present study was to identify the significant NBI findings to diagnose esophageal mucosal high-grade neoplasia.

METHODS

Between August 2007 and January 2009, we detected 59 new superficial esophageal lesions. The video images of NBI were recorded digitally. NBI findings such as brownish dots (dilated intra-epithelial papillary capillary loop [IPCL]), tortuous IPCL, elongated IPCL, caliber change in IPCL, variety in IPCL shapes, demarcation line, brownish epithelium, and protrusion or depression were evaluated using the video images. The association between each NBI finding and diagnosis of mucosal high-grade neoplasia, and intra- and interobserver agreement was evaluated.

RESULTS

In univariate analysis, brownish epithelium, brownish dots, tortuous IPCL, variety in IPCL shapes and demarcation line were associated significantly with diagnosis of mucosal high-grade neoplasia. In multivariate analysis, brownish epithelium and brownish dots were confirmed to be independent factors. Odds ratios were 25.5 (95% confidence interval [CI]: 2.4-268) for brownish epithelium and 19.3 (95% CI: 1.8-207.7) for brownish dots. Intraobserver agreement was substantial for brownish epithelium and brownish dots. Interobserver agreement was moderate in brownish epithelium and brownish dots.

CONCLUSIONS

Brownish epithelium and brownish dots were confirmed to be significant and reproducible NBI findings in the diagnosis of squamous mucosal high-grade neoplasia of the esophagus. Initial assessment of esophageal lesions should be done based on these findings.

A useful procedure for observing the cervical esophagus via the hypopharynx

OBJECTIVE

The aim of the study was to evaluate upper gastrointestinal endoscopy with movable over tube (i.e., the movable over tube method) for observing the hypopharynx to cervical esophagus, for use in treatment, and to determine its safety.

METHODS

The study population consisted of 28 patients (23 men, 5 women; a mean age of 66.6 years old; age range of 50-80 years old). The patients consisted of nine cases of globus sensation, eight cases of hypopharyngeal cancer (post-chemoradiotherapy), three cases of hypopharyngeal cancer (untreated), two cases of hoarseness, two cases of unknown primary carcinoma, two cases of foreign body, one case of esophageal cancer, and one case of dysphagia. We used upper gastrointestinal endoscopy with movable over tube to examine the hypopharynx to the cervical esophagus in subjects.

RESULTS

With the movable over tube method, which was performed under pharyngeal surface anesthesia and an infusion of diazepam (5-10mg/kg body weight), one could observe from the hypopharynx to cervical esophagus without any blind spots. There were no complications after the examination.

CONCLUSIONS

The results suggest that the movable over tube method is an easy, useful, and safe method to observe the region from the hypopharynx to the cervical esophagus.

Role of narrow-band imaging and high-definition television in the surveillance of head and neck squamous cell cancer after chemo- and/or radiotherapy

Narrow-band imaging (NBI) is an endoscopic technique enhancing mucosal vasculature and better identifying superficial carcinomas due to their neo-angiogenic pattern. NBI accuracy is increased by combination with a high-definition television (HDTV) camera. The aim of this report was to evaluate the diagnostic improvement of NBI +/- HDTV in the evaluation of head and neck squamous cell cancer (HNSCC) previously treated by chemo-radiotherapy (CHT-RT) or RT. A total of 390 patients affected by HNSCC were prospectively evaluated by NBI and white light (WL) endoscopy +/- HDTV between April 2007 and April 2009 at a single academic institution. Among them, we focused on 59 (15%) patients who received CHT-RT or RT as part of their treatment. Of 59 patients, 13 (22%) showed adjunctive preoperative NBI findings when compared to the standard WL examination. These findings were always confirmed by intraoperative HDTV NBI, while only eight (62%) were visible with HDTV WL. Of 13 lesions, 12 received histopathologic confirmation (from carcinoma in situ to invasive carcinoma). The sensitivity of flexible NBI, HDTV WL, and HDTV NBI was 100, 66 and 100%, respectively. The specificity was 98, 100, and 98%. The positive predictive value was 92, 100, and 92%. The negative predictive value was 100, 94, and 100%. The accuracy was 98, 91, and 98%. NBI +/- HDTV after CHT-RT or RT was of value in detecting tumor persistence (n = 2), early recurrences (n = 6), and metachronous tumors (n = 4). By contrast, only 1 of 59 (2%) patients was found to be false positive.

Detecting early oral cancer: narrowband imaging system observation of the oral mucosa microvasculature

The aim of this study was to analyze and describe the intrapapillary capillary loops (IPCL), which are a feature of early oral neoplastic lesions, using a narrowband imaging (NBI) system. Forty-one patients (26 men, 15 women; mean age, 52.34 years; range, 23-83 years) presenting with non-neoplastic or neoplastic lesions, and normal cases, were examined using the prototype Evis Lucera Spectrum (Olympus Co.). The images were analyzed and an IPCL classification was devised. All normal cases (n=10) had regularly distributed capillary loops of the same shape (type I). Non-neoplastic lesions (n=8) had mild changes of the capillary loops (types II and III) and neoplastic lesions (n=23) were irregularly distributed and had several loop shapes (types III and IV). The microvascular organization of non-neoplastic lesions was notably different from that of neoplastic lesions. A brownish area was found in five cases of early carcinoma. The narrowband imaging system is a potential approach for clinically analyzing microvascular organization and IPCL. It could be useful for diagnosing oral squamous cell carcinoma at an earlier stage and for determining the margin of resection.

Early detection of superficial squamous cell carcinoma in the head and neck region and esophagus by narrow band imaging: a multicenter randomized controlled trial

PURPOSE

Most of the esophageal squamous cell carcinomas (ESCCs) and cancers of the head and neck (H&N) region are diagnosed at later stages. To achieve better survival, early detection is necessary. We compared the real-time diagnostic yield of superficial cancer in these regions between conventional white light imaging (WLI) and narrow band imaging (NBI) in high-risk patients.

PATIENTS AND METHODS

In a multicenter, prospective, randomized controlled trial, 320 patients with ESCC were randomly assigned to primary WLI followed by NBI (n = 162) or primary NBI followed by WLI (n = 158) in a back-to-back fashion. The primary aim was to compare the real-time detection rates of superficial cancer in the H&N region and the esophagus between WLI and NBI. The secondary aim was to evaluate the diagnostic accuracy of these techniques.

RESULTS

NBI detected superficial cancer more frequently than did WLI in both the H&N region and the esophagus (100% v 8%, P < .001; 97% v 55%, P < .001, respectively). The sensitivity of NBI for diagnosis of superficial cancer was 100% and 97.2% in the H&N region and the esophagus, respectively. The accuracy of NBI for diagnosis of superficial cancer was 86.7% and 88.9% in these regions, respectively. The sensitivity and accuracy were significantly higher using NBI than WLI in both regions (P < .001 and P = .02 for the H&N region; P < .001 for both measures for the esophagus, respectively).

CONCLUSION

NBI could be the standard examination for the early detection of superficial cancer in the H&N region and the esophagus.

Usefulness of narrow-band imaging for detecting the primary tumor site in patients with primary unknown cervical lymph node metastasis

Objective

We sometimes experienced patients with primary unknown cervical lymph node metastasis. In such cases, if computed tomography, magnetic resonance imaging, laryngoscopy and gastrointestinal endoscopy cannot detect a primary site, there is no other effective method to identify a possible primary tumor. We investigated whether narrow-band imaging can detect a possible primary tumor in such.

Methods

Forty-six patients with primary unknown cervical lymph node metastasis were surveyed about primary tumors, from January 2003 to December 2006. All cervical lymph nodes were histologically proved to be squamous cell carcinoma by fine-needle aspiration cytology. Narrow-band imaging combined with magnifying endoscopy was used to identify the primary site in the head and neck region and cervical esophagus. Histological analysis was performed for all suspicious lesions by a biopsy specimen.

Results

Twenty-six lesions were suspected to be cancerous lesions by narrow-band imaging in the head and neck region. Sixteen lesions in 16 (35%, 16/46) patients were squamous cell carcinoma. Ten lesions were located in the hypopharynx and the remaining six lesions were located in the oropharynx. White light endoscopy could not point out any lesion.

Conclusions

Narrow-band imaging endoscopy can detect possible primary cancer in patients with primary unknown cervical lymph node metastasis.

Narrow-band imaging endoscopy with magnification is useful for detecting metachronous superficial pharyngeal cancer in patients with esophageal squamous cell carcinoma

BACKGROUND AND AIMS

Head and neck cancers, especially pharyngeal cancers, as well as esophageal cancers frequently coexist either synchronously or metachronously, but most cases of pharyngeal cancer are detected at an advanced stage resulting in poor prognosis. The aim of this study is to evaluate the effectiveness of using narrow-band imaging (NBI) endoscopy with magnification for early detection of pharyngeal cancer on patients following their treatment for esophageal squamous cell carcinoma (SCC).

METHODS

This case series was conducted at the National Cancer Center Hospital in Tokyo between April and October 2005 and included 424 consecutive patients for surveillance endoscopy who had previously undergone chemoradiotherapy (CRT) and/or surgery for esophageal SCC. Observation of the pharyngeal region was randomly conducted on 91 patients using NBI endoscopy with magnification (NBI group) and 333 patients using conventional white light endoscopy (control group).

RESULTS

The detection rate for pharyngeal cancer was significantly higher using NBI endoscopy with magnification (10.9%; 10/91) compared with conventional endoscopy (1.2%; 4/333) (P < 0.0001). In particular, the detection rate in CRT patients was significantly higher in the NBI group (12.9%; 7/54) than the control group (0.5%; 1/191) (P < 0.0001). In addition, diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the NBI group were 100% (10/10), 97.5% (79/81), 97.8% (89/91), 83.3% (10/12) and 100% (79/79), respectively.

CONCLUSION

NBI endoscopy with magnification is a promising technique for detecting superficial pharyngeal cancer at an early stage in patients previously treated for esophageal SCC.

Evaluation of visualization of squamous cell carcinoma of esophagus and pharynx using an autofluorescence imaging videoendoscope system

BACKGROUND AND AIM

An autofluorescence imaging (AFI) videoendoscope system produces pseudo-color images combining autofluorescence and green reflectance, with the utility of this system previously confirmed for the diagnosis of bronchial squamous cell carcinoma (SCC). Our aim was to evaluate visualization of esophageal and pharyngeal SCC comparing AFI with white light endoscopy (WLE).

METHODS

Thirty-two patients with superficial esophageal SCC and 11 patients with superficial pharyngeal SCC diagnosed in other hospitals were enrolled in this prospective study. We observed the esophagus and pharynx with WLE followed by AFI and took both WLE and AFI images of the esophageal and pharyngeal SCC. Three experienced endoscopists subsequently evaluated the visualization quality of images from both systems on a three-tier scale: visible, illegible and invisible.

RESULTS

A total of 39 superficial esophageal SCC were diagnosed with 20, 11 and eight lesions classified as visible, illegible and invisible, respectively, by WLE compared to 31, three and five lesions, respectively, using AFI. Using AFI, 79% of superficial esophageal SCC lesions were visible, compared to only 51% with WLE (P < 0.05). In addition, 12 superficial pharyngeal SCC were diagnosed with four, five and three lesions considered as visible, illegible and invisible, respectively, using WLE in contrast to nine, three and 0 lesions, respectively, by AFI. Thus, using AFI, 75% of superficial pharyngeal SCC lesions were visible compared with only 33% with WLE (P = 0.13).

CONCLUSION

The AFI system appears to be more useful than WLE for early diagnosis of SCC of the esophagus and pharynx.

Pilot study on confocal endomicroscopy for determination of the depth of squamous cell esophageal cancer in vivo

BACKGROUND AND AIM

Confocal endomicroscopy is ultra-high-magnification endoscopy with histological observation during ongoing endoscopy. We planned a pilot study of the diagnosis of the depth of esophageal cancer using confocal endomicroscopy for treatment strategies.

METHODS

Patients had 14 superficial esophageal cancers and one dysplasia. The depth of neoplasms in 15 lesions was confirmed by endoscopic mucosal resection or surgery. We examined the rate of delineation and compared results of confocal imaging with histological findings. We classified two cellular and three microvascular patterns on confocal endomicroscopic images: CP-N for normal squamous mucosa and CP-Ca for cancerous lesion; VP-type A for normal squamous mucosa; VP-type B for T1a-EP and T1a-LPM cancers; and VP-type C for T1a-MM or a more invasive cancer pattern. We measured diameters of microvessels for the three patterns of confocal endomicroscopic images and histological specimens.

RESULTS

The rate of delineation was 73.3% (11/15) for esophageal cancer. The results of confocal imaging coincided well with microvessel distribution on horizontal histology. Two endoscopists blindly diagnosed the two types by cellular pattern and the three types by vascular pattern: their overall accuracies were 96% and 89% for the cellular pattern and 85% and 85% for the vascular pattern, respectively. The k value of the cellular pattern and the vascular pattern diagnosis was 0.84 and 0.75, respectively.

CONCLUSION

Scoring and quantification of confocal endomicroscopic images may be useful for the differential diagnosis and diagnosis of superficial invasion by squamous cell carcinoma.

Diagnosis of colorectal lesions with the magnifying narrow-band imaging system

BACKGROUND

Narrow-band imaging (NBI) emphasizes the surface microvasculature of the GI tract and may help in detecting small neoplasms.

OBJECTIVE

The aim of this study was to clarify the value of the NBI system in tissue characterization and differential diagnosis.

DESIGN

A prospective study.

SETTING

Digestive Disease Center of Showa University Northern Yokohama Hospital.

PATIENTS

The subjects were 495 patients who, from January 2006 to June 2007, underwent a complete colonoscopic examination. A total of 617 lesions were evaluated in the 495 patients (33 hyperplastic polyps, 532 adenomas, 52 submucosally invasive [T1] cancers).

RESULTS

Most hyperplastic polyps showed a faint pattern. The vascular patterns of adenomas were mainly the network pattern or the dense pattern. The major vascular patterns of cancers were the irregular pattern and the sparse pattern. The irregular pattern was characteristic for protruded or flat-elevated cancers, whereas the sparse pattern was unique for depressed cancers. When we assumed that the faint pattern was diagnostic for hyperplastic polyps, we could differentiate between neoplastic and non-neoplastic lesions with a sensitivity of 90.9% and a specificity of 97.1%. Likewise, irregular and sparse patterns were assumed to be indices of massively invasive submucosal cancer, the sensitivity was 100%, the specificity was 95.8%, and the accuracy rate was 96.1%.

LIMITATIONS

This study was performed at a single center.

CONCLUSIONS

The NBI system was valuable for distinguishing between neoplastic and non-neoplastic lesions, as well as between cancers and adenomas. Vascular pattern analysis can also be a promising tool for determining treatment selection, either endoscopy or surgery.

Improving visualization techniques by narrow band imaging and magnification endoscopy

Endoscopy plays an important role in the early detection of gastrointestinal tract neoplasms. Using conventional white light or dye-based image enhanced endoscopy, it has been difficult to assess pre-malignant and early neoplastic lesions precisely. However, narrow band imaging (NBI) dramatically improves the detection of these lesions, particularly in combination with magnifying endoscopy. This allows the endoscopist to accomplish accurate diagnosis. Such enhanced detection of pre-malignant and early neoplastic lesions in the gastrointestinal tract should allow better targeting of biopsy, improved and more appropriate treatment, and thereby contribute to optimal quality of life and patient survival.

Prospective study of early detection of pharyngeal superficial carcinoma with the narrowband imaging laryngoscope

BACKGROUND

The newly developed narrowband imaging (NBI) gastrointestinal endoscope makes possible the detection of superficial carcinoma in the oropharynx and hypopharynx, which is difficult with the conventional laryngoscope. Here, we investigated whether the combined use of laryngoscope with NBI allows the detection of superficial carcinoma in this region.

METHODS

A total of 51 superficial, histologically confirmed lesions in 29 patients were studied. The quality of visualization of superficial carcinoma in the oropharynx and hypopharynx using the NBI-equipped laryngoscope was evaluated in comparison with the results by conventional laryngoscopy.

RESULTS

The NBI laryngoscope provided better detection of the irregular microvascular pattern of carcinoma than the conventional laryngoscope (p <.05) and better visualization of the demarcation line (p <.05), and thus significantly better visualization of the lesions.

CONCLUSION

The NBI laryngoscope may play an important role in the diagnosis and treatment of superficial carcinoma in the oropharynx and hypopharynx.

Narrow band imaging in the diagnosis of intra-epithelial and invasive laryngeal squamous cell carcinoma: a preliminary report of two cases

Narrow band imaging (NBI) is a novel optical technique that enhances the diagnostic capability of the gastrointestinal endoscope (GIE) by illuminating the intraepithelial papillary capillary loop (IPCL) using narrow bandwidth filters in a red-green-blue sequential illumination system (CV-260SL processor and CLV-260SL light source, Olympus Optical Co. Ltd, Tokyo, Japan). The NBI filter sets (415 nm and 540 nm) are selected to obtain fine images of the microvascular structure. Because 415 nm is the hemoglobin absorption band, capillaries on the mucosal surface can be seen most clearly at this wavelength. NBI is able to represent more clearly both capillary patterns and the boundary between different types of tissue, which are necessary for diagnosing a tumor in its early stage (Gono K, Yamazaki K, Doguchi N, Nonami T, Obi T, Yamaguchi M, et al. Endoscopic observation of tissue by narrow band illumination. Opt Rev 2003;10:211-215, Gono K, Obi T, Yamaguchi M, Ohyama N, Machida H, Sano Y, et al. Appearance of enhanced tissue feature in narrow-band endoscopic imaging. J Biomed Opt 2004;9:568-577). We present two patients with laryngeal squamous cell carcinoma in whom the spread and the depth of invasion was evaluated with transnasal GIE equipped with NBI. Based on our results, the vascular neoplastic changes of carcinoma in situ of the larynx could be similar to carcinoma in situ of the esophagus.