In vivo histological diagnosis for gastric cancer using endocytoscopy

AIM To examine usefulness of virtual biopsy using endocytoscopy by comparing the in vivo endocytoscopic and histopathological images of gastric cancers.METHODS Endocytoscopy was performed in 30 patients with early gastric cancer. Of these, 26 patients showed well differentiated adenocarcinomas, while 4 patients showed poorly differentiated adenocarcinomas(including one signet ring cell carcinoma). Cancerous and non-cancerous areas were observed after double staining with 0.05% crystal violet and 0.1% methylene blue. The endocytoscopic images obtained were evaluated by an expert endoscopist and an expert pathologist without knowledge of patient clinical data, and endocytoscopic and histopathological diagnoses were compared.RESULTS The endocytoscopic images of the cancerous area were assessed as evaluable in 25(83.3%) and 27(90%) patients by endoscopist A and pathologist B, respectively, and those of the non-cancerous area as evaluable in 28(93.3%) and 23(76.7%) patients by the endoscopist and pathologist, respectively. The sensitivity, specificity, and diagnostic accuracy of gastric cancer diagnosis using evaluable endocytoscopic images were 88.0% and 92.9%, and 90.6% by endoscopist A, and 88.9% and 91.3%, and 90.0% by pathologist B, respectively. Evaluation of the diagnostic concordance rate between the endoscopist and the pathologist by inter-observer agreement calculation revealed no significant difference between the two observers. The inter-observer agreement(κ-value) for endocytoscopic diagnosis was 0.745. CONCLUSION Endocytoscopy is useful for the differentiation of cancerous from non-cancerous gastric mucosa, making it a promising tool for virtual biopsy.

Prospective real-time evaluation of diagnostic performance using endocytoscopy in differentiating neoplasia from nonneoplasia for colorectal diminutive polyps(≤ 5 mm)

AIM To clarify the diagnostic performance of endocytoscopy for differentiation between neoplastic and nonneoplastic colorectal diminutive polyps.METHODS Patients who underwent endocytoscopy between October and December 2016 at Sano Hospital were prospectively recruited. When diminutive polyps(≤5 mm) were detected, the lesions were evaluated by endocytoscopy after being stained with 0.05% crystal violet and 1% methylene blue. The diminutivepolyps were classified into five categories(EC 1 a, 1 b, 2, 3 a, and 3 b). Endoscopists were asked to take a biopsy from any lesion diagnosed as EC1 b(indicator of hyperplastic polyp) or EC2(indicator of adenoma). We have assessed the diagnostic performance of endocytoscopy for EC2 and EC1 b lesions by comparison with the histopathology of the biopsy specimen. RESULTS A total of 39 patients with 63 diminutive polyps were analyzed. All polyps were evaluated by endocytoscopy. The mean polyp size was 3.3 ± 0.9 mm. Among the 63 diminutive polyps, 60 were flat and 3 were pedunculated. The mean time required for EC observation, including the time for staining with crystal violet and methylene blue, was 3.0 ± 1.9 min. Histopathologic evaluation showed that 13 polyps were hyperplastic and 50 were adenomas. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of EC2 for adenoma compared with EC1 b for hyperplastic polyp were 98.0%, 92.3%, 96.8%, 98.0% and 92.3%, respectively. There were only two cases of disagreement between the endoscopic diagnosis made by endocytoscopy and the corresponding histopathological diagnosis.CONCLUSION Endocytoscopy showed a high diagnostic performance for differentiating between neoplastic and non-neoplastic colorectal diminutive polyps, and therefore has the potential to be used for "real-time histopathology".

In vivo gastric mucosal histopathology using endocytoscopy

AIM:To study the ability of endocytoscopy to identify normal gastric mucosa and to exclude Helicobacter pylori(H.pylori) infection.METHODS:Endocytoscopic examination of the gastric corpus and antrum was performed in 70 consecutive patients.Target biopsy specimens were also obtained from the assessed region and multiple H.pylori tests were performed.The normal endocytoscopy patterns of the corpus and antrum were divided into the normal pit-dominant type(n-Pit) or the normal papilladominant type(n-Pap), respectively characterized as either regular pits with capillary networks or round, smooth papillary structures with spiral capillaries.On the other hand, normal mucosa was defined as mucosa not demonstrating histological abnormalities, including inflammation and atrophy.RESULTS:The sensitivity and specificity of n-Pit for normal mucosa in the gastric corpus were 94.4%and 97.1%,respectively,whereas those of n-Pap for normal mucosa in the antrum were 92.0%and 86.7%,respectively.The positive predictive values of n-Pit and n-Pap for H.pylori-negative tissue were 88.6%and 93.1%,respectively,and their negative predictive values for H.pylori-negative tissues were 42.9%and41.5%,respectively.The inter-observer agreement for determining n-Pit and n-Pap for normal mucosa were0.857 and 0.769,respectively,which is considered reliable.CONCLUSION:N-Pit and n-Pap,seen using EC,are considered useful predictors of normal mucosa and theabsence of H.pylori infection.

Assessment of the diagnostic performance and interobserver variability of endocytoscopy in Barrett's esophagus:A pilot ex-vivo study

AIM: To investigate a classification of endocytoscopy (ECS) images in Barrett’s esophagus (BE) and evaluate its diagnostic performance and interobserver variability.

Small invasive colon cancer with adenoma observed by endocytoscopy: A case report

Endocytoscopy is a next-generation endoscopic system that facilitates real-time histopathologic endoscopic diagnosis of colorectal lesions by virtue of its 520×maximum magnification.CASE SUMMARY We present the case of a 63-year-old man with sigmoid colon cancer who was regularly referred for follow-up colonoscopy after endoscopic resection of T1 rectal cancer.Colonoscopy revealed a 12 mm reddish polyp,including a depression and a flat area in the sigmoid colon.Endocytoscopic observation showed unclear gland formation and agglomeration of distorted nuclei(depression),suggesting a submucosal invasive(T1)cancer.In the flat area,slitlike smooth lumens and regular pattern of fusiform nuclei were found,suggesting an adenoma.On the basis of these endocytoscopic findings,we predicted this lesion as T1 cancer(depression)with adenoma(flat area)and performed endoscopic resection corresponding to the final histopathological diagnosis.CONCLUSION We could perform an optical diagnosis of T1 sigmoid cancer with adenoma by using endocytoscopy before treatment.

Artificial intelligence assisted endocytoscopy: A novel eye in endoscopy

Over the past few years,emerging new approaches in endoscopic imaging technologies facilitate a high-quality assessment of lesions found in the gastrointestinal(GI)tract.Endocytoscopy(EC),as a novel tool in endoscopy,aids the more accurate evaluation of superficial mucosal surface.This review article aims to represent the most relevant information related to the latest EC technology and its clinical application in the lower GI tract diagnostic.We discuss EC-computer-aided diagnosis capability to differentiate between non-neoplastic and neoplastic lesion that offers a closer look to in-vivo assessment and diagnosis of cancerous tissue.Nevertheless,artificial-assisted EC diagnostics could also be employed with benefits in patients with inflammatory bowel disease(IBD)by accurately highlighting the presence of mucosal injury.In our review we included those studies comprising data about colonoscopy with narrow banding imaging and computer-aided diagnosis,as well as EC.Last but not least,artificial-assisted EC facilitates in-vivo diagnosis of the lower GI tract and may,in the future,remodel the field of in-vivo endoscopic diagnosis of colorectal lesions,representing another step towards the so-called optical biopsy.

Sessile serrated adenoma/polyps: Where are we at in 2016?

It is currently known that colorectal cancers(CRC) arise from 3 different pathways: the adenoma to carcinoma chromosomal instability pathway(50%-70%); the mutator "Lynch syndrome" route(3%-5%); and the serrated pathway(30%-35%). The World Health Organization has classified serrated polyps into three types of lesions: hyperplastic polyps(HP),sessile serrated adenomas/polyps(SSA/P) and traditional serrated adenomas(TSA),the latter two strongly associated with development of CRCs. HPs do not cause cancer and TSAs are rare. SSA/P appear to be the responsible precursor lesion for the development of cancers through the serrated pathway. Both HPs and SSA/Ps appear morphologically similar. SSA/P are difficult to detect. The margins are normally inconspicuous. En bloc resection of these polyps can hence be troublesome. A careful examination of borders,submucosal injection of a dye solution(for larger lesions) and resection of a rim of normal tissue around the lesion may ensure total eradication of these lesions.

New endoscopic approaches in IBD

Recent advances in endoscopic imaging techniques have revolutionized the diagnostic approach of patients with inflammatory bowel disease(IBD).New,emerging endoscopic imaging techniques visualized a plethora of new mucosal details even at the cellular and subcellular level.This review offers an overview about new endoscopic techniques,including chromoendoscopy,magnification endoscopy,spectroscopy,confocal laser endomicroscopy and endocytoscopy in the face of IBD.

Advanced gastrointestinal endoscopic imaging forinflammatory bowel diseases

Gastrointestinal luminal endoscopy is of paramount importance for diagnosis, monitoring and dysplasia surveillance in patients with both, Crohn's disease and ulcerative colitis. Moreover, with the recent recognition that mucosal healing is directly linked to the clinical outcome of patients with inflammatory bowel disorders, a growing demand exists for the precise, timely and detailed endoscopic assessment of superficial mucosal layer. Further, the novel field of molecular imaging has tremendously expanded the clinical utility and applications of modern endoscopy, now encompassing not only diagnosis, surveillance, and treatment but also the prediction of individual therapeutic responses. Within this review, we describe how novel endoscopic approaches and advanced endoscopic imaging methods such as high definition and high magnification endoscopy, dye-based and dye-less chromoendoscopy, confocal laser endomicroscopy, endocytoscopy and molecular imaging now allow for the precise and ultrastructural assessment of mucosal inflammation and describe the potential of these techniques for dysplasia detection.

Real-time histology with the endocytoscope

Endoscopic Imaging has progressed tremendously over the last few decades. Novel imaging technologies such as high-resolution and high-magnification white light endoscopy, narrow band imaging, optimal band imaging, auto? ourescence imaging and optical coherence tomography not only aid the endoscopist in detecting malignant or pre-malignant lesions but also assist in predicting histology. Recently, the introduction of Endocytoscopy (EC) and Confocal Endomicroscopy has taken us into a new realm of diagnostic endoscopy. With the ability to magnify up to 1000 ×, cellular structures can be visualized in real-time. This advance in technology could potentially lead to a paradigm shift negating the need to obtain biopsies. EC is, however, still in the early stages of development and further research needs to be carried out before it can be accepted as standard practice. This review will focus on the diagnostic utility of the Endocytoscope.

High technology imaging in digestive endoscopy

A thorough endoscopic visualization of the digestive mucosa is essential for reaching an accurate diagnosis and to treat the different lesions. Standard white light endoscopes permit a good mucosa examination but, nowadays, the introduction of powerful endoscopic instrumentations increased ability to analyze the fi nest details. By applying dyes and zoom-magnifi cation endoscopy further architectural detail of the mucosa can be elucidated. New computed virtual chromoendoscopy have further enhanced optical capabilities for the evaluation of submucosal vascolar pattern. Recently, confocal endomicroscopy and endocytoscopy were proposed for the study of ultrastructural mucosa details. Because of the technological contents of powerful instrumentation, a good knowledge of implemented technologies is mandatory for the endoscopist, nowadays. Nevertheless, there is a big confusion about this topic. We will try to explain these technologies and to clarify this terminology.

Endoscopic imaging:How far are we from real-time histology?

Currently,in gastrointestinal endoscopy there is increasing interest in high resolution endoscopic technologies that can complement high-definition white light endoscopy by providing real-time subcellular imaging of the epithelial surface.These 'optical biopsy' technologies offer the potential to improve diagnostic accuracy and yield,while facilitating real-time decision-making.Although many endoscopic techniques have preliminarily shown high accuracy rates,these technologies are still evolving.This review will provide an overview of the most promising high-resolution imaging technologies,including high resolution microendoscopy,optical coherence tomography,endocytoscopy and confocal laser endoscopy.This review will also discuss the application and current limitations of these technologies for the early detection of neoplasia in Barrett's esophagus,ulcerative colitis and colorectal cancer.

Endocytoscopic visualization of squamous cell islands within Barrett's epithelium

AIM: To study the endocytoscopic visualization of squamous cell islands within Barrett's epithelium. METHODS: Endocytoscopy (ECS) has been studied in the surveillance of Barrett's esophagus, with controversial results. In initial studies, however, a soft catheter type endocytoscope was used, while only methylene blue dye was used for the staining of Barrett's mucosa. Integrated type endocytoscopes (GIF-Q260 EC, Olympus Corp, Tokyo, Japan) have been recently developed, with the incorporation of a high-power magnifying endocytoscope into a standard endoscope together with narrow-band imaging (NBI). Moreover, double staining with a mixture of 0.05% crystal violet and 0.1% of methylene blue (CM) during ECS enables higher quality images comparable to conventional hematoxylin eosin histopathological images.RESULTS: In vivo endocytoscopic visualization of papillary squamous cell islands within glandular Barrett's epithelium in a patient with long-segment Barrett's esophagus is reported. Conventional white light endoscopy showed typical long-segment Barrett's esophagus, with small squamous cell islands within normal Barrett's mucosa, which were better visualized by NBI endoscopy. ECS after double CM staining showed regular Barrett's esophagus, while higher magnification (×480) revealed the orifices of glandular structures better. Furthermore, typical squamous cell papillary protrusion, classified as endocytoscopic atypia classification (ECA) 2 according to ECA, was identified within regular glandular Barrett's mucosa. Histological examination of biopsies taken from the same area showed squamous epithelium within glandular Barrett's mucosa, corresponding well to endocytoscopic findings. CONCLUSION: To our knowledge, this is the first report of in vivo visualization of esophageal papillary squamous cell islands surrounded by glandular Barrett's epithelium.

Ultra high magnification endoscopy: Is seeing really believing?

Endoscopy is an indispensible diagnostic and thera-peutic instrument for gastrointestinal diseases. Endo-cytoscopy and confocal endomicroscopy are two types of ultra high magnification endoscopy techniques.Standard endoscopy allows for 50 × magnification,whereas endocytoscopy can magnify up to 1400 × and confocal endomicroscopy can magnify up to 1000 ×.These methods open the realm of real time micros copicevaluation of the GI tract, including cellular and subcellular structures. Confocal endomicroscopy has the additional advantage of being able to visualize subsurface structures. The use of high magnification endoscopy inconjunction with standard endoscopy allows for a real-time microscopic assessment of areas with macroscopic abnormalities, providing "virtual biopsies" with valuable information about cellular and subcellular changes. Thiscan minimize the number of biopsies taken at the time of endoscopy. The use of this technology may assistin detecting premalignant or malignant changes at anearlier state, allowing for earlier intervention and treatment. High magnification endoscopy has shown promising results in clinical trials for Barrett's esophagus,esophageal adenocarcinoma, esophageal squamous cell cancer, gastric cancer, celiac disease, colorectalcancer, and inflammatory bowel disease. As the use of high magnification endoscopy techniques increases,the clinical applications will increase as well. Of the two systems, only confocal endomicroscopy is currently commercially available. Like all new technologies there will be an initial learning curve before operators become proficient in obtaining high quality images and discerning abnormal from normal pathology. Validatedcriteria for the diagnosis of the various gastrointestinal diseases will need to be developed for each method. Inthis review, the basic principles of both modalities are discussed, along with their clinical applic ability and limitations.

Brown slits for colorectal adenoma crypts on conventional magnifying endoscopy with narrow band imaging using the X1 system

BACKGROUND Accurate diagnosis of colorectal premalignant polyps,including adenomas,is vital in clinical practice.AIM To investigate the diagnostic yields of novel findings of brown slits for adenomas.METHODS Patients who underwent colonoscopy at the Toyoshima Endoscopy Clinic were enrolled.Polyps sized≥5 mm suspected of adenomas or clinically significant serrated polyps were included in the study.We defined the surface structures of colorectal polyps,which were brown curves inside and along the tubular glands identified using a combination of a new X1 system(Olympus Corporation)and a conventional magnifying colonoscope with non-staining narrow band imaging(NBI),as brown slits.The brown slits corresponded to slit-like lumens on endocytoscopy and histological crypt openings of an adenoma.We evaluated the diagnostic performance of brown slits for adenoma.RESULTS A total of 108 Lesions from 62 patients were eligible.The average age was 60.4 years and 41.9%were male.The mean polyp size was 7.45±2.83 mm.Fifty-seven lesions were positive for brown slits.Histopathological diagnosis comprised 59 low-grade tubular adenomas,16 sessile serrated lesions,and 33 hyperplastic polyps.Among 59 adenomas,56(94.9%)were positive for brown slits.Among 16 sessile serrated lesions,0(0%)was positive for brown slits.Among 33 hyperplastic polyps,1(3.0%)was positive for brown slits.The sensitivity,specificity,and accuracy of brown slits for adenoma were 94.9%,98.0%,and 96.3%,respectively.The positive predictive value and negative predictive value of brown slits for adenoma were also excellent for 98.2%,and 94.1%,respectively.CONCLUSION Brown slits on conventional magnifying endoscopy with non-staining NBI using the X1 system were useful for diagnosing colorectal adenoma.The new endoscopy system could be examined using new standards.

Beyond white light endoscopy: The role of optical biopsy in inflammatory bowel disease

In this review,we will discuss the use of two optical biopsy modalities in inflammatory bowel disease(IBD).The two techniques reviewed here are confocal laser endomicroscopy and endocytoscopy.We will describe the technical performance of the procedure,discuss the clinical indications for optical biopsy in IBD,and highlight active research areas with respect to the pathogenesis of IBD.Clinical indications for optical biopsies in IBD include assessment of mucosal inflammation,dysplasia detection and evaluation of cell shedding for disease relapse.Research application in the area of barrier dysfunction will also be discussed.

New application of endocytoscope for histopathological diagnosis of colorectal lesions

BACKGROUND The endocytoscope with ultra-high magnification(x 520)allows us to observe the cellular structure of the colon epithelium during colonoscopy,known as virtual histopathology.We hypothesized that the endocytoscope could directly observe colorectal histopathological specimens and store them as endocyto-pathological images by the endoscopists without a microscope,potentially saving the burden on histopathologists.AIM To assess the feasibility of endocyto-pathological images taken by an endoscopist as adequate materials for histopathological diagnosis.METHODS Three gastrointestinal pathologists were invited and asked to diagnose 40 cases of endocyto-pathological images of colorectal specimens.Each case contained seven endocyto-pathological images taken by an endoscopist,consisting of one loupe image,three low-magnification images,and three ultra-high magnification images.The participants chose hyperplastic polyp or low-grade adenoma for 20 cases of endocyto-pathological images(10 hyperplastic polyps,and 10 Low-grade adenomas in conventional histopathology)in study 1 and high-grade adenoma/shallow invasive cancer or deep invasive cancer for 20 cases[10 tumor in situ/T1a and 10 T1b]in study 2.We investigated the agreement between the histopathological diagnosis using the endocyto-pathological images and conventional histopathological diagnosis.RESULTS Agreement between the endocyto-pathological and conventional histopathological diagnosis by the three gastrointestinal pathologists was 100%(95%CI:94.0%–100%)in studies 1 and 2.The interobserver agreement among the three gastrointestinal pathologists was 100%,and theκcoefficient was 1.00 in both studies.CONCLUSION Endocyto-pathological images were adequate and reliable materials for histopathological diagnosis.