Confocal laser endomicroscopy as a new diagnostic tool for poorly differentiated gastric adenocarcinoma

Gastric cancer(GC)is a multifactorial disease,where both environmental and genetic features can have an impact on its occurrence and development.GC represents one of the leading causes of cancer-related deaths worldwide.GC is most frequent in males and is believed to arise from a series of premalignant lesions.The detection of GC at an early stage is crucial because early GC,which is an invasive stomach cancer confined to the mucosal or submucosal lining,may be curable with a reported 5-year survival rate of more than 90%.Advanced GC usually has a poor prognosis despite current treatment standards.The diagnostic efficacy of conventional endoscopy(with light endoscopy)is currently limited.Confocal laser endomicroscopy is a novel imaging technique that allows real-time in vivo histological examination of mucosal surfaces during endoscopy.Confocal laser endomicroscopy may be of great importance in the surveillance of precancerous gastric lesions and in the diagnosis of GC.In this editorial we commented on the article about this topic published by Lou et al in the recent issue of the World Journal of Clinical Cases.

Diagnosis of poorly differentiated adenocarcinoma of the stomach by confocal laser endomicroscopy:A case report

BACKGROUND In recent years,confocal laser endomicroscopy(CLE)has become a new endoscopic imaging technology at the microscopic level,which is extensively performed for real-time in vivo histological examination.CLE can be performed to distinguish benign from malignant lesions.In this study,we diagnosed using CLE an asymptomatic patient with poorly differentiated gastric adenocarcinoma.CASE SUMMARY A 63-year-old woman was diagnosed with gastric mucosal lesions,which may be gastric cancer,in the small curvature of the stomach by gastroscopy.She consented to undergo CLE for morphological observation of the gastric mucosa.Through the combination of CLE diagnosis and postoperative pathology,the intraoperative CLE diagnosis was considered to be reliable.According to our experience,CLE can be performed as the first choice for the diagnosis of gastric cancer.CONCLUSION CLE has several advantages over pathological diagnosis.We believe that CLE has great potential in the diagnosis of benign and malignant gastric lesions.

Corneal nerve changes by anti-glaucoma medications examined by in vivo confocal microscopy

AIM:To evaluate the effects of antiglaucoma eye drops on corneal nerves by in vivo confocal microscopy(IVCM).METHODS:This study comprised 79 patients diagnosed with glaucoma and 16 healthy control individuals.Among the glaucoma patients,54 were treated with medication,while 25 remained untreated.Central corneal images were evaluated by IVCM,and then ACCMetrics was used to calculate the following parameters:corneal nerve fiber density(CNFD),branch density(CNBD),fiber length(CNFL),total branch density(CTBD),fiber area(CNFA),fiber width(CNFW),and fractal dimension(CNFrD).The correlation between IVCM parameters and drugs was evaluated using non-parametric measurements of Spearman’s rank correlation coefficient.RESULTS:The CNFD was reduced in glaucoma groups compared to healthy subjects(P<0.01).Patients using anti-glaucoma medications exhibited poorer confocal parameters compared to untreated patients.As the number of medications and usage count increased,CNFD,CNBD,CNFL,CTBD,CNFA,and CNFrD experienced a decline,while CNFW increased(all P<0.01).For the brinzolamide-therapy group,there was a significant decrease in CNFD and CNFL compared to the other monotherapy groups(P<0.001).In the absence of medication,CNFD in males was lower than that in females(P<0.05).Among patients under medication therapy,CNFD remained consistent between males and females.CONCLUSION:Antiglaucoma eye drops affect the microstructure of corneal nerves.IVCM and ACCMetrics are useful tools that could be used to evaluate the corneal nerve changes.

Confocal laser endomicroscopy for gastric neoplasm

Confocal laser endomicroscopy(CLE)is a novel endoscopic modality that provides real-time histological information via high-resolution magnified view of the mucosa.CLE has a higher sensitivity,specificity,and diagnostic accuracy in detecting atrophic gastritis as compared to chromoendoscopy and narrow-band imaging.It can even predict low-grade and high-grade intraepithelial neoplasia by analyzing gastric pit patterns.CLE may have some advantages over the standard biopsy protocol,such as higher diagnostic yield and fewer biopsy requirements.Its diagnostic accuracy in detecting superficial gastric cancer is higher than that of white-light endoscopy.Inherent limitations,such as a narrow field of vision,can be surpassed by technological advancements and integration with other detection methods.Artificial intelligence holds promise in automated analysis of histopathological images.Thus,CLE can be helpful in screening for early gastric cancer and may help reduce the risk of complications from repeated biopsies,such as mucosal damage,bleeding,and infection.

Confocal Laser Endomicroscopy in the Field of Esophageal Diseases

Confocal laser endomicroscopy (CLE) is a new endoscopic imaging technology that allows real-time, high-resolution observation of tomographic images of mucosal cells and subcellular levels in vivo, detecting microscopic structural changes in mucosal morphology, and its in vivo immediate pathological diagnostic capability can avoid delays in mucosal pathological diagnosis and reduce the pain caused by repeated biopsies. CLE is known as “optical biopsy” and compared with other endoscopic techniques, it has obvious advantages. CLE systems include probe-based confocal laser endomicroscopy (pCLE) and endoscope-based confocal laser endomicroscopy (eCLE). Since 2006, CLE has been widely used for the evaluation of various lesions in the digestive system, including esophageal, gastric, and colonic neoplasia, pancreatic cysts and solid lesions, and inflammatory bowel disease. The advent of CLE has made in vivo microscopic imaging possible, which has changed the endoscopic screening and diagnosis of multiple gastrointestinal (GI) lesions. However, the value of its use in GI diseases is still controversial. In this review, we focus on the application of CLE in the field of esophageal diseases.

In situ observation of the dissolution kinetics of Al_(2)O_(3) particles in CaO–Al_(2)O_(3)–SiO_(2) slags using laser confocal scanning microscopy

The dissolution kinetics of Al_(2)O_(3) in CaO-Al_(2)O_(3) SiOslags was studied using a high-temperature confocal scanning laser microscope at 1773 to 1873 K.The results show that the controlling step during the Al_(2)O_(3) dissolution was the diffusionin molten slag.It was found that the dissolution curves of Al_(2)O_(3) particles were hardly agreed with the traditional boundary layer diffusion model with the increase of the CaO/Al_(2)O_(3) ratio of slag.A modified diffusion equation considering slag viscosity was developed to study the dissolution mechanism of Al_(2)O_(3) in slag.Diffusion coefficients of Al_(2)O_(3) in slag were calculated as 2.8×10to 4.1×10m~2/s at the temperature of 1773-1873 K.The dissolution rate of Al_(2)O_(3) increased with higher temperature,CaO/Al_(2)O_(3),and particle size.A new model was shown to be v_(Al_(2)O_(3))=0.16×r_(0)^(1.58)×x^(3.52)×(T-T_(mp))^(1.11)to predict the dissolution rate and the total dissolution time of Al_(2)O_(3) inclusions with various sizes,where vAl_(2)O_(3) is the dissolution rate of Al_(2)O_(3) in volume,μm^(3)/s;x is the value of CaO/Al_(2)O_(3) mass ratio;R_(0) is the initial radius of Al_(2)O_(3),μm;T is the temperature,K;T_(mp) is the melting point of slag,K.

Revealing the F_actin Networks in Interphase Nuclei of Garlic Clove Cells by Confocal Fluorescence Microscopy

The interphase nuclei of parenchyma cells and epidermal cells of garlic ( Allium sativum L.) clove were labelled with rabbit anti_actin antibody and FITC_conjugated goat anti_rabbit IgG antibody. The authors observed results with fluorescence microscopy and confocal laser scanning microscopy. The nuclei showed prominent green_yellow fluorescence, indicating the presence of actin in the nuclei. Fluorescence examination with TRITC_phalloidin showed distinctive red fluorescence in the nuclei, indicating that F_actin is present in the nuclei. Confocal laser scanning microscopy indicated the presence of F_actin containing network structures in the nuclei, but the network structures were absent and the nuclei still showed red fluorescence when the cells were treated with cytochalasin D before fixation; the red fluorescence in the nuclei was hard to be observed when the cells were treated with unlabelled phalloidin before the cells were stained with TRITC_phalloidin. These results indicate that F_actin is in the nuclei and forms network structures in the nuclei of garlic cells.

In vivo subsurface morphological and functional cellular and subcellular imaging of the gastrointestinal tract with confocal mini-microscopy

AIM： To evaluate a newly developed hand-held confocal probe for in vivo microscopic imaging of the complete gastrointestinal tract in rodents. METHODS： A novel rigid confocal probe （diameter 7 mm） was designed with optical features similar to the flexible endomicroscopy system for use in humans using a 488 nm single line laser for fluorophore excitation, Light emission was detected at 505 to 750 nm. The field of view was 475 μm × 475 μm. Optical slice thickness was 7 μm with a lateral resolution of 0.7 μm. Subsurface serial images at different depths （surface to 250 μm） were generated in real time at 1024 × 1024 pixels （0.8 frames/s） by placing the probe onto the tissue in gentle, stable contact. Tissue specimens were sampled for histopathological correlation.RESULTS： The esophagus, stomach, small and large intestine and meso, liver, pancreas and gall bladder were visualised in vivo at high resolution in n = 48 mice. Real time microscopic imaging with the confocal minimicroscopy probe was easy to achieve. The different staining protocols （fluorescein, acriflavine, FITC-labelled dextran and L. esculentum lectin） each highlighted specific aspects of the tissue, and in vivo imaging correlated excellently with conventional histology. In vivo blood flow monitoring added a functional quality to morphologic imaging.CONCLUSION： Confocal microscopy is feasible in vivo allowing the visualisation of the complete GI tract at high resolution even of subsurface tissue structures. The new confocal probe design evaluated in this study is compatible with laparoscopy and significantly expands the field of possible applications to intra-abdominal organs. It allows immediate testing of new in vivo staining and application options and therefore permits rapid transfer from animal studies to clinical use in patients.

Clinical impact of confocal laser endomicroscopy in the management of gastrointestinal lesions with an uncertain diagnosis

To evaluate the clinical impact of confocal laser endomicroscopy (CLE) in the diagnosis and management of patients with an uncertain diagnosis. METHODSA retrospective chart review was performed. Patients who underwent CLE between November 2013 and October 2015 and exhibited a poor correlation between endoscopic and histological findings were included. Baseline characteristics, indications, previous diagnostic studies, findings at the time of CLE, clinical management and histological results were analyzed. Interventions based on CLE findings were also analyzed. We compared the diagnostic accuracy of CLE and target biopsies of surgical specimens. RESULTSA total of 144 patients were included. Of these, 51% (74/144) were female. The mean age was 51 years old. In all, 41/144 (28.4%) lesions were neoplastic (13 bile duct, 10 gastric, 8 esophageal, 6 colonic, 1 duodenal, 1 rectal, 1 ampulloma and 1 pancreatic). The sensitivity, specificity, positive predictive value, negative predictive value, and observed agreement when CLE was used to detect N-lesions were 85.37%, 87.38%, 72.92%, 93.75% and 86.81%, respectively. Cohen’s Kappa was 69.20%, thus indicating good agreement. Changes in management were observed in 54% of the cases. CONCLUSIONCLE is a new diagnostic tool that has a significant clinical impact on the diagnosis and treatment of patients with uncertain diagnosis.

Confocal endomicroscopy:Is it time to move on?

Confocal laser endomicroscopy permits in-vivo microscopy evaluation during endoscopy procedures. It can be used in all the parts of the gastrointestinal tract and includes: Esophagus,stomach,small bowel,colon,biliary tract through and endoscopic retrograde cholangiopancreatography and pancreas through needles during endoscopic ultrasound procedures. Many researches demonstrated a high correlation of results between confocal laser endomicroscopy and histopathology in the diagnosis of gastrointestinal lesions; with accuracy in about 86% to 96%. Moreover,in spite that histopathology remains the gold-standard technique for final diagnosis of any diseases; a considerable number of misdiagnosis rate could be present due to many factors such as interpretation mistakes,biopsy site inaccuracy,or number of biopsies. Theoretically; with the diagnostic accuracy rates of confocal laser endomicroscopy could help in a daily practice to improve diagnosis and treatment management of the patients. However,it is still not routinely used in the clinical practice due to many factors such as cost of the procedure,lack of codification and reimbursement in some countries,absence of standard of care indications,availability,physician imageinterpretation training,medico-legal problems,and the role of the pathologist. These limitations are relative,and solutions could be found based on new researches focused to solve these barriers.

Classification of histological severity of Helicobacter pylori-associated gastritis by confocal laser endomicroscopy

AIM: To classify the histological severity of Helicobacter pylori (H. pylori) infection-associated gastritis by confocal laser endomicroscopy (CLE). METHODS: Patients with upper gastrointestinal symptoms or individuals who were screened for gastric cancer were enrolled in this study. Histological severity of H. pylori infection-associated gastritis was graded according to the established CLE criteria. Diagnostic value of CLE for histo-logical gastritis was investigated and compared with that of white light endoscopy (WLE). Targeted biopsies from the sites observed by CLE were performed. RESULTS: A total of 118 consecutive patients with H. pylori infection-associated gastritis were enrolled in this study. Receiver operating characteristic curve analysis showedthat the sensitivity and specifi city of CLE were 82.9% and 90.9% for the diagnosis of H. pylori infection, 94.6% and 97.4% for predicting gastric normal mucosa, 98.5% and 94.6% for predicting histological active inflammation, 92.9% and 95.2% for predicting glan-dular atrophy, 98.6% and 100% for diagnosing intes-tinal metaplasia, respectively. Post-CLE image analysis showed that goblet cells and absorptive cells were the two most common parameters on the CLE-diagnosed intestinal metaplasia (IM) images (P < 0.001). More his-tological lesions of the stomach could be found by CLE than by WLE (P < 0.001). CONCLUSION: CLE can accurately show the histological severity of H. pylori infection-associated gastritis. Mapping IM by CLE has a rather good diagnostic accuracy.

Probe based confocal laser endomicroscopy of the pancreatobiliary system

AIM:To review applications of confocal laser endomicroscopy(CLE) in pancreatobiliary lesions and studies that assessed training and interpretation of images. METHODS: A computerized literature search was performed using OVID MEDLINE, EMBASE, Cochrane library, and the ISI Web of Knowledge from 1980 to October 2014. We also searched abstracts from major meetings that included the Digestive Disease Week, Canadian Digestive Disease Week and the United European Gastroenterology Week using a combination of controlled vocabulary and text words related to p CLE, confocal, endomicroscopy, probe-based confocal laser endomicroscopy, and bile duct to identify reports of trials. In addition, recursive searches and crossreferencing was performed, and manual searches of articles identified after the initial search was also completed. We included fully published articles and those in abstract form. Given the relatively recent introduction of CLE we included randomized trials and cohort studies.R E S U LT S : In the evaluation of indeterminate pancreatobiliary strictures CLE with ERCP compared to ERCP alone can increase the detection of cancerous strictures with a sensitivity of(98% vs 45%) andhas a negative predictive value(97% vs 69%), but decreased the specificity(67% vs 100%) and the positive predictive value(71% vs 100%) when compared to index pathology. Modifications in the classification systems in indeterminate biliary strictures have increased the specificity of p CLE from 67% to 73%. In pancreatic cystic lesions there is a need to develop similar systems to interpret and characterize lesions based on CLE images obtained. The presence of superficial vascular network predicts serous cystadenomas accurately. Also training in acquiring and interpretation of images is feasible in those without any prior knowledge in CLE in a relatively simple manner and computer-aided diagnosis software is a promising innovation. CONCLUSION: The role of p CLE in the evaluation of pancreatobiliary disorders might be better suited for those with an intermediate and low probability.

Effects of contact lens wearing on keratoconus:a confocal microscopy observation

AIM： To evaluate the corneal cell morphology of new keratoconus patients wearing two different types of rigid gas-permeable（RGP） contact lenses for 1y.METHODS： Thirty nine eyes of 39 new keratoconus patients were selected and randomly fitted with two types of RGP contact lenses.Group 1 had 21 eyes with regular rigid gas-permeable（RRGP） contact lens and rest 18 eyes were in group 2 with specially designed rigid gas-permeable（SRGP） contact lens.Corneal cell morphology was evaluated using a slit scanning confocal microscope at no-lens wear and after 1y of contact lens wearing.RESULTS： After 1y of contact lens wearing in group 1,the mean anterior and posterior stromal keratocyte density were significantly less（P=0.006 and P=0.001,respectively） compared to no-lens wear.The mean cell area of anterior and posterior stromal keratocyte were also significantly different（P=0.005 and P=0.001） from no-lens wear.The anterior and posterior stromal haze increased by 18.74% and 23.81%,respectively after 1y of contact lens wearing.Whereas in group 2,statistically significant changes were observed only in cell density ＆ area of anterior stroma（P=0.001 and P=0.001,respectively） after 1y.While,level of anterior and posterior stromal haze increased by 16.67% and 11.11% after 1y of contact lens wearing.Polymegathism and pleomorphism also increased after 1y of contact lens wearing in both the contact lens groups.CONCLUSION： Confocal microscopy observation shows the significant alterations in corneal cell morphology of keratoconic corneas wearing contact lenses especially in group 1.The type of contact lens must be carefully selected to minimize changes in corneal cell morphology.

In vivo corneal confocal microscopy in diabetes: Where we are and where we can get

In vivo corneal confocal microscopy(IVCCM) is a novel,reproducible, easy and noninvasive technique that allows the study of the different layers of the cornea at a cellular level. As cornea is the most innervated organ of human body, several studies investigated the use of corneal confocal microscopy to detect diabetic neuropathies, which are invalidating and deadly complications of diabetes mellitus. Corneal nerve innervation has been shown impaired in subjects with diabetes and a close association between damages of peripheral nerves due to the diabetes and alterations in corneal sub-basal nerve plexus detected by IVCCM has been widely demonstrated. Interestingly, these alterations seem to precede the clinical onset of diabetic neuropathies, paving the path for prevention studies. However, some concerns still prevent the full implementation of this technique in clinical practice. In this review we summarize the most recent and relevant evidences about the use of IVCCM for the diagnosis of peripheral sensorimotor polyneuropathy and of autonomic neuropathy in diabetes. New perspectives and current limitations are also discussed.

Confocal laser endomicroscopy in the “in vivo” histological diagnosis of the gastrointestinal tract

Recent technological advances in miniaturization have allowed for a confocal scanning microscope to be integrated into a conventional flexible endoscope,or into trans-endoscopic probes,a technique now known as confocal endomicroscopy or confocal laser endomicroscopy.This newly-developed technology has enabled endoscopists to collect real-time in vivo histological images or "virtual biopsies" of the gastrointestinal mucosa during endoscopy,and has stimulated significant interest in the application of this technique in clinical gastroenterology.This review aims to evaluate the current data on the technical aspects and the utility of this new technology in clinical gastroenterology and its potential impact in the future,particularly in the screening or surveillance of gastrointestinal neoplasia.

Advanced diagnostics for pancreatic cysts: Confocal endomicroscopy and molecular analysis

Technological advances and the widespread use of medical imaging have led to an increase in the identification of pancreatic cysts in patients who undergo crosssectional imaging. Current methods for the diagnosis and risk-stratification of pancreatic cysts are suboptimal, resulting in both unnecessary surgical resection and overlooked cases of neoplasia. Accurate diagnosis is crucial for guiding how a pancreatic cyst is managed, whether with surveillance for low-risk lesions or surgical resection for high-risk lesions. This review aims to summarize the current literature on confocal endomicroscopy and cyst fluid molecular analysis for the evaluation of pancreatic cysts. These recent technologies are promising adjuncts to existing approaches with the potential to improve diagnostic accuracy and ultimately patient outcomes.

Clinical features and in vivo confocal microscopy assessment in 12 patients with ocular cicatricial pemphigoid

AIM： To describe the clinical features and microstructural characteristics assessed by in vivo confocal microscopy（IVCM） in patients with ocular cicatricial pemphigoid（OCP）.· METHODS： A descriptive, uncontrolled case series study. Patients diagnosed with OCP were examined by clinical history, slit-lamp biomicroscopy features and IVCM images. The results of direct immunofluorescence（DIF） biopsies and indirect immunofluorescence（IIF） were also recorded. Local and systemic immunosuppressive therapy were administered and adjusted according to response.·RESULTS： A total of 12 consecutive OCP patients（7male, 5 female; mean age 60.42 ±10.39y） were recruited.All patients exhibited bilateral progressive conjunctival scarring and recurrent chronic conjunctivitis was the most frequent clinical pattern. The mean duration of symptoms prior to diagnosis of OCP was 2.95 ±2.85y（range： 5mo to 10y）. The Foster classification varied from stage I to IV and 20 eyes（83%） were within or greater than Foster stage Ⅲ on presentation. Two of the 12patients（17%） demonstrated positive DIF; 3 of the 12（25%） patients reported positive IIF. The mean duration of the follow-up period was 20.17 ±11.88mo（range： 6 to48mo）. IVCM showed variable degrees of abnormality in the conjuctiva-cornea and conjuctival scarring was detected in all the involved eyes. Corneal stromal cell activation and dendritic cell infiltration presented asocular surface inflammation, ocular surface keratinization along with the destroyed Vogt palisades was noted in eyes with potential limbal stem cell deficiency. After treatment, remission of ocular surface inflammation was achieved in all the patients, 18 eyes（75%） remained stable, 6 eyes（25%） had recurrent conjunctivitis and cicatrization in 2 eyes（8%） was progressing.· CONCLUSION： As an autoimmune disease, OCP manifests as variable degrees of clinical and laboratory abnormalities with both local and systemic immunosuppressive treatment playing important roles in disease therapy. IVCM can be as a valuable non-invasive technique to assess ocular surface changes in a cellular level with a potential value for providing diagnostic evidence and monitoring therapeutic effects during follow-up.

Appraisal of needle-based confocal laser endomicroscopy inthe diagnosis of pancreatic cysts

Nearly 2.5% of cross-sectional imaging studies will report a finding of a cystic pancreatic lesion. Eventhough most of these are incidental findings, it remains very concerning for both patients and treating clinicians. Differentiating and predicting malignant transformation in pancreatic cystic lesions is clinically challenging. Current evaluation of suspicious cystic lesions includes a combination of radiologic imaging, endoscopic ultrasound(EUS) and cyst fluid analyses. Despite these attempts, precise diagnostic stratification among nonmucinous, mucinous, and malignant cystic lesions is often not possible until surgical resection. EUS-guided needle based confocal laser endomicroscopy(n CLE) for evaluation of pancreatic cysts is emerging as a powerful technique with remarkable potential. Though limited imaging data from 3 large clinical trials(INSPECT, DETECT and CONTACT) are currently the reference standard for n CLE imaging, nonetheless these have not been validated in large studies. The aim of this review article is to review the evolving role of EUS-guided n CLE in management of pancreatic cystic lesions in terms of its significance, adverse events, limitations, and implications.

EFFECT OF THE TOTAL SAPONIN OF DIPSACUS ASPER ON INTRACELLULAR FREE CALCIUM CONCENTRATION IN THE CELLULAR MODEL OF ALZHEIMER'S DISEASE-SCANNING CONFOCAL MICROSCOPY

Objective To study the effect of ginsenoside Rb1 and total saponin of dipsacus asper on intracellular free calcium concentration mediated by β amyloid protein.So as to lay a foundation for developing effective Chinese traditional medicine to treat Alzheimer’s disease.Methods The technique of laser scanning confocal microscopy combining primary cultured neurons was adopted to quantitatively analyze the change of [Ca 2+ ] i.Results The [Ca 2+ ] i of primary cultured hippocampal neurons was nmol·L -1 on basal levels.Control group showed obvious change of calcium vibration,[Ca 2+ ] i was elevated to nmol·L -1 .The peak of [Ca 2+ ] i of Rb1 group reached nmol·L -1 and was lower than that of control group .The tSDA group displayed distinct change of calcium vibration too,and [Ca 2+ ] i reached nmol·L -1 .There was a significant difference in [Ca 2+ ] i between control and tSDA group .Conclusion The research indicated that one of mechanisms by which Rb1 and tSDA protected the neurons was to maintain the balance of [Ca 2+ ] i.

Investigation of confocal microscopy for differentiation of renal cell carcinoma versus benign tissue.Can an optical biopsy be performed?

Objective:Novel optical imaging modalities are under development with the goal of obtaining an“optical biopsy”to efficiently provide pathologic details.One such modality is confocal microscopy which allows in situ visualization of cells within a layer of tissue and imaging of cellular-level structures.The goal of this study is to validate the ability of confocal microscopy to quickly and accurately differentiate between normal renal tissue and cancer.Methods:Specimens were obtained from patients who underwent robotic partial nephrectomy for renal mass.Samples of suspected normal and tumor tissue were extracted from the excised portion of the kidney and stained with acridine orange.The stained samples were imaged on a Nikon E600 C1 Confocal Microscope.The samples were then submitted for hematoxylin and eosin processing and read by an expert pathologist to provide a gold-standard diagnosis that can later be compared to the confocal images.Results:This study included 11 patients,17 tissue samples,and 118 confocal images.Of the 17 tissue samples,10 had a gold-standard diagnosis of cancer and seven were benign.Of 118 confocal images,66 had a gold-standard diagnosis of cancer and 52 were benign.Six confocal images were used as a training set to train eight observers.The observers were asked to rate the test images on a six point scale and the results were analyzed using a web based receiver operating characteristic curve calculator.The average accuracy,sensitivity,specificity,and area under the empirical receiver operating characteristic curve for this study were 91%,98%,81%,and 0.94 respectively.Conclusion:This preliminary study suggest that confocal microscopy can be used to distinguish cancer from normal tissue with high sensitivity and specificity.The observers in this study were trained quickly and on only six images.We expect even higher performance as observers become more familiar with the confocal images.