Reflectance confocal microscopy and features of melanocytic lesions: an internet-based study of the reproducibility of terminology

[Translated article] Reflectance Confocal Microscopy Terminology in Spanish: A Delphi Consensus Study

The terminology used to describe reflectance confocal microscopy (RCM) findings in both melanocytic and nonmelanocytic lesions has been standardized in English. We convened a panel of Spanish-speaking RCM experts and used the Delphi method to seek consensus on which Spanish terms best describe RCM findings in this setting. The experts agreed on 52 terms: 28 for melanocytic lesions and 24 for nonmelanocytic lesions. The resulting terminology will facilitate homogenization, leading to a better understanding of structures, more standardized descriptions in clinical registries, and easier interpretation of clinical reports exchanged between dermatologists.

Reflectance Confocal Microscopy Terminology in Spanish: A Delphi Consensus Study

The terminology used to describe reflectance confocal microscopy (RCM) findings in both melanocytic and nonmelanocytic lesions has been standardized in English. We convened a panel of Spanish-speaking RCM experts and used the Delphi method to seek consensus on which Spanish terms best describe RCM findings in this setting. The experts agreed on 52 terms: 28 for melanocytic lesions and 24 for nonmelanocytic lesions. The resulting terminology will facilitate homogenization, leading to a better understanding of structures, more standardized descriptions in clinical registries, and easier interpretation of clinical reports exchanged between dermatologists.

Reflectance confocal microscopy - Consensus terminology glossary in Brazilian Portuguese for normal skin, melanocytic and non-melanocytic lesions

BACKGROUND

Currently, there is no uniform and official terminology in Portuguese for reflectance confocal microscopy analysis, despite the increasing number of Brazilian dermatologists using this new tool.

OBJECTIVE

To present the terminology in Brazilian Portuguese for the description of reflectance confocal microscopy and establish the first Brazilian consensus on terms related to normal skin and cutaneous tumors.

METHODS

10 Brazilian specialists from different institutions and states of Brazil were selected to evaluate the best corresponding terms in Portuguese for normal skin, melanocytic and non-melanocytic tumors. The terms used were translated from international consensuses in the English language. The modified Delphi method was used to create the consensus in 3 steps.

RESULTS

The terms considered the most appropriate in the Portuguese language to describe the findings of normal skin, melanocytic and non-melanocytic lesions in the reflectance confocal microscopy analysis were presented.

STUDY LIMITATIONS

The limitations of the present study include the number of participants and limited regional representation (only two of the five Brazilian regions were represented).

CONCLUSION

This Brazilian consensus represents an opportunity for dermatologists and physicians specializing in cutaneous oncology to become familiar with reflectance confocal microscopy, propagating the technique in clinical and research environments to stimulate national and international publications on this subject.

In vivo optical imaging-guided targeted sampling for precise diagnosis and molecular pathology

Conventional tissue sampling can lead to misdiagnoses and repeated biopsies. Additionally, tissue processed for histopathology suffers from poor nucleic acid quality and/or quantity for downstream molecular profiling. Targeted micro-sampling of tissue can ensure accurate diagnosis and molecular profiling in the presence of spatial heterogeneity, especially in tumors, and facilitate acquisition of fresh tissue for molecular analysis. In this study, we explored the feasibility of performing 1–2 mm precision biopsies guided by high-resolution reflectance confocal microscopy (RCM) and optical coherence tomography (OCT), and reflective metallic grids for accurate spatial targeting. Accurate sampling was confirmed with either histopathology or molecular profiling through next generation sequencing (NGS) in 9 skin cancers in 7 patients. Imaging-guided 1–2 mm biopsies enabled spatial targeting for in vivo diagnosis, feature correlation and depth assessment, which were confirmed with histopathology. In vivo 1-mm targeted biopsies achieved adequate quantity and high quality of DNA for next-generation sequencing. Subsequent mutational profiling was confirmed on 1 melanoma in situ and 2 invasive melanomas, using a 505-gene mutational panel called Memorial Sloan Kettering-Integrated mutational profiling of actionable cancer targets (MSK-IMPACT). Differential mutational landscapes, in terms of number and types of mutations, were found between invasive and in situ melanomas in a single patient. Our findings demonstrate feasibility of accurate sampling of regions of interest for downstream histopathological diagnoses and molecular pathology in both in vivo and ex vivo settings with broad diagnostic, therapeutic and research potential in cutaneous diseases accessible by RCM-OCT imaging.

Dermoscopic and clinical predictors of reflectance confocal microscopy patterns of typical nevi on the back and legs: A cross-sectional study

BACKGROUND

Nevus phenotype is a marker of melanoma risk. In vivo prediction of microscopic pattern is needed to more precisely classify nevi.

OBJECTIVE

To identify dermoscopic and clinical predictors of microscopic patterns of typical nevi.

METHODS

We used reflectance confocal microscopy (RCM) to classify microscopic patterns of nevi. We prospectively accrued adults presenting for periodic skin screening and imaged, with dermoscopy and RCM, 3 randomly selected nevi from the upper and lower back and lower extremity. RCM patterns were classified into ring, clod, meshwork, and composite types. Logistic regression was used to identify best predictors of RCM pattern.

RESULTS

The study included 310 nevi from 112 participants (mean age 44 years; 51 women). Dermoscopic reticular pattern correlated most frequently (59.9%) with RCM ring pattern, dermoscopic globular with RCM composite (56.6%) and RCM clod (35.9%), dermoscopic complex with RCM composite (76.3%), and dermoscopic homogenous with RCM clod (50.8%). Integrating dermoscopic pattern with contour, diameter, color, and anatomic location of nevi improved prediction of microscopic patterns beyond dermoscopy alone. The dermoscopic clinical regression model correctly classified lesions to RCM ring versus RCM clod in 90% and to RCM ring versus RCM composite patterns in 81%.

LIMITATIONS

The study was restricted to adults, back and lower extremities, and typical nevi.

CONCLUSIONS

Integrating dermoscopic patterns with clinical attributes may improve prediction of microscopic patterns of nevi.

Reflectance confocal microscopy terminology glossary for melanocytic skin lesions: A systematic review

BACKGROUND

There is lack of uniformity in the reflectance confocal microscopy (RCM) terminology for melanocytic lesions.

OBJECTIVE

To review published RCM terms for melanocytic lesions and identify redundant, synonymous terms.

METHODS

A systematic review of original research articles adhering to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines was conducted until August 15, 2018. Two investigators gathered all published RCM terms used to describe melanoma and melanocytic nevi. Synonymous terms were grouped based on similarity in definition and in histopathologic correlation.

RESULTS

Out of 156 full-text screened articles, 59 studies met the inclusion criteria. We identified 209 terms; 191 (91.4%) corresponding to high-magnification/cellular-level terms and 18 (8.6%) corresponding to low-magnification/architectural patterns terms. The overall average use frequency of RCM terms was 3.1 times (range, 1-31). By grouping of individual RCM terms based on likely synonymous definitions and by eliminating terms lacking clear definition, the total number of RCM terms could be potentially reduced from 209 to 40 terms (80.8% reduction).

LIMITATIONS

Non-English and non-peer-reviewed articles were excluded.

CONCLUSIONS

This systematic review of published RCM terms identified significant terminology redundancy. It provides the basis for subsequent terminology consensus on melanocytic neoplasms.

Evaluation of a Combined Reflectance Confocal Microscopy-Optical Coherence Tomography Device for Detection and Depth Assessment of Basal Cell Carcinoma

Importance

The limited tissue sampling of a biopsy can lead to an incomplete assessment of basal cell carcinoma (BCC) subtypes and depth. Reflectance confocal microscopy (RCM) combined with optical coherence tomography (OCT) imaging may enable real-time, noninvasive, comprehensive three-dimensional sampling in vivo, which may improve the diagnostic accuracy and margin assessment of BCCs.

Objective

To determine the accuracy of a combined RCM-OCT device for BCC detection and deep margin assessment.

Design, Setting, and Participants

This pilot study was carried out on 85 lesions from 55 patients referred for physician consultation or Mohs surgery at Memorial Sloan Kettering Skin Cancer Center in Hauppauge, New York. These patients were prospectively and consecutively enrolled in the study between January 1, 2017, and December 31, 2017. Patients underwent imaging, with the combined RCM-OCT probe, for previously biopsied, histopathologically confirmed BCCs and lesions clinically or dermoscopically suggestive of BCC. Only patients with available histopathologic examination after imaging were included.

Main Outcomes and Measures

Improvements in sensitivity, specificity, and diagnostic accuracy for BCC using the combined RCM-OCT probe as well as the correlation between OCT-estimated depth and histopathologically measured depth were investigated.

Results

In total, 85 lesions from 55 patients (27 [49%] were female and 28 [51%] were male with a median [range] age of 59 [21-90] years) were imaged. Imaging was performed on 25 previously biopsied and histopathologically confirmed BCCs and 60 previously nonbiopsied but clinically or dermoscopically suspicious lesions. Normal skin and BCC features were correlated and validated with histopathologic examination. In previously biopsied lesions, residual tumors were detected in 12 of 25 (48%) lesions with 100% sensitivity (95% CI, 73.5%-100%) and 23.1% specificity (95% CI, 5.0%-53.8%) for combined RCM-OCT probe. In previously nonbiopsied and suspicious lesions, BCCs were diagnosed in 48 of 60 (80%) lesions with 100% sensitivity (95% CI, 92.6%-100%) and 75% specificity (95% CI, 42.8%-94.5%). Correlation was observed between depth estimated with OCT and depth measured with histopathologic examination: the coefficient of determination (R2) was 0.75 (R = 0.86; P < .001) for all lesions, 0.73 (R = 0.85; P < .001) for lesions less than 500 μm deep, and 0.65 (R = 0.43; P < .001) for lesions greater than 500 μm deep.

Conclusions and Relevance

Combined RCM-OCT imaging may be prospectively used to comprehensively diagnose lesions suggestive of BCC and triage for treatment. Further validation of this device must be performed on a larger cohort.

A Systematic Review and Meta-Analysis of the Accuracy of in VivoReflectance Confocal Microscopy for the Diagnosis of Primary Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common cancer worldwide and its incidence is constantly rising. Early diagnosis and treatment can significantly reduce patient morbidity and healthcare costs. The value of reflectance confocal microscopy (RCM) in non-melanoma skin cancer diagnosis is still under debate. This systematic review and meta-analysis were conducted to assess the diagnostic accuracy of RCM in primary BCC. PubMed, Google Scholar, Scopus, and Web of Science databases were searched up to July 05, 2019, to collect articles concerning primary BCC diagnosis through RCM. The studies’ methodological quality was assessed by the QUADAS-2 tool. The meta-analysis was conducted using Stata 13.0, RevMan 5.0, and MetaDisc 1.4 software. We included 15 studies totaling a number of 4163 lesions. The pooled sensitivity and specificity were 0.92 (95% CI, 0.87–0.95; I² = 85.27%) and 0.93 (95% CI, 0.85–0.97; I² = 94.61%), the pooled positive and negative likelihood ratios were 13.51 (95% CI, 5.8–31.37; I² = 91.01%) and 0.08 (95% CI, 0.05–0.14; I² = 84.83%), and the pooled diagnostic odds ratio was 160.31 (95% CI, 64.73–397.02; I² = 71%). Despite the heterogeneity and risk of bias, this study demonstrates that RCM, through its high sensitivity and specificity, may have a significant clinical impact on the diagnosis of primary BCC.

The use of in vivo reflectance confocal microscopy for the diagnosis of melanoma

INTRODUCTION

The use of reflectance confocal microscopy (RCM) for imaging the skin non-invasively raised constantly during the last decade. One of the main field of application is skin cancer diagnosis, and in particular melanoma diagnosis. Several studies have investigated the diagnostic accuracy of RCM as compared to dermoscopic examination, and its value in enhancing early diagnosis of dermoscopic difficult melanomas. Areas covered: The purpose of this paper was to review the principles behind RCM image acquisition as well as to describe and discuss key RCM features of melanoma. Moreover, we conducted a literature search in order to highlight the current available evidence about RCM sensitivity and specificity in the diagnosis of melanoma. Expert commentary: During the last decade, we assisted at the increasing interest in non invasive imaging tools for the diagnosis of skin cancer. RCM is one of the most studied of a series of diagnostic methods that are emerging in the field of melanoma imaging. Most probably in the future, RCM will be more frequently available in tertiary referral centres, thus the knowledge of the pros and contra of the tool and its clinical applicability is of upmost importance in order to allow correct referrals with the final aim of improving diagnostic accuracy.

Melanoma types by in vivo reflectance confocal microscopy correlated with protein and molecular genetic alterations: A pilot study

Cutaneous melanoma (CM) is one of the most prevalent skin cancers, which lacks both a prognostic marker and a specific and lasting treatment, due to the complexity of the disease and heterogeneity of patients. Reflectance confocal microscopy (RCM) in vivo analysis is a versatile approach offering immediate morphological information, enabling the identification of four primary cutaneous RCM CM types. Whether RCM CM types are associated with a specific protein and molecular genetic profiles at the tissue level remains unclear. The current pilot study was designed to identify potential correlations between RCM CM types and specific biological characteristics, combining immunohistochemistry (IHC) and molecular analyses. Eighty primary CMs evaluated at patient bedside with RCM (type 1 [19, 24%], type 2 [12, 15%], type 3 [7, 9%] and type 4 [42, 52%]) were retrospectively evaluated by IHC stains (CD271, CD20, CD31, cyclin D1), fluorescence in situ hybridization FISH for MYC gain and CDKN2A loss and molecular analysis for somatic mutations (BRAF, NRAS and KIT). RCM CM types correlated with markers of stemness property, density of intra-tumoral lymphocytic B infiltrate and cyclin D1 expression, while no significant association was found with blood vessel density nor molecular findings. RCM CM types show a different marker profile expression, suggestive of a progression and an increase in aggressiveness, according to RCM morphologies.

Reflectance confocal microscopy terminology glossary for nonmelanocytic skin lesions: A systematic review

BACKGROUND

There is lack of uniformity in reflectance confocal microscopy (RCM) terminology for nonmelanocytic lesions (NMLs).

OBJECTIVE

To review published RCM terms for NMLs and identify likely synonymous terms.

METHODS

We conducted a systematic review of original research articles published up to August 19, 2017, adhering to Preferred Reporting Items for Systemic Reviews and Meta-Analyses guidelines. Two investigators gathered all published RCM terms used to describe basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and seborrheic keratosis/solar lentigo/lichen planus-like keratosis (SK/SL/LPLK). Synonymous terms were grouped on the basis of similarity in definition and histopathologic correlates.

RESULTS

The inclusion criteria was met by 31 studies. Average frequency of use per term was 1.6 (range 1-8). By grouping synonymous terms, the number of terms could be reduced from 58 to 18 for BCC, 58 to 36 for SCC, 23 to 12 for SK/SL/LPLK, and from 139 to 66 terms (52.5% reduction) in total. The frequency of term usage stratified by anatomic layer (suprabasal epidermis vs epidermal basal layer, dermoepidermal junction, and superficial dermis) was 27 (25.7%) versus 78 (74.2%) for BCC; 60 (64.5%) versus 33 (34.5%) for SCC, and 15 (45.4%) versus 18 (54.5%) for SK/SL/LPLK, respectively.

LIMITATIONS

Articles that were not peer reviewed were excluded.

CONCLUSION

Systematic review of published RCM terms provides the basis for future NMLs terminology consensus.

Reflectance confocal microscopy for diagnosing cutaneous melanoma in adults

BACKGROUND

Melanoma has one of the fastest rising incidence rates of any cancer. It accounts for a small percentage of skin cancer cases but is responsible for the majority of skin cancer deaths. Early detection and treatment is key to improving survival; however, anxiety around missing early cases needs to be balanced against appropriate levels of referral and excision of benign lesions. Used in conjunction with clinical or dermoscopic suspicion of malignancy, or both, reflectance confocal microscopy (RCM) may reduce unnecessary excisions without missing melanoma cases.

OBJECTIVES

To determine the diagnostic accuracy of reflectance confocal microscopy for the detection of cutaneous invasive melanoma and atypical intraepidermal melanocytic variants in adults with any lesion suspicious for melanoma and lesions that are difficult to diagnose, and to compare its accuracy with that of dermoscopy.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; and seven other databases. We studied reference lists and published systematic review articles.

SELECTION CRITERIA

Studies of any design that evaluated RCM alone, or RCM in comparison to dermoscopy, in adults with lesions suspicious for melanoma or atypical intraepidermal melanocytic variants, compared with a reference standard of either histological confirmation or clinical follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on QUADAS-2). We contacted authors of included studies where information related to the target condition or diagnostic threshold were missing. We estimated summary sensitivities and specificities per algorithm and threshold using the bivariate hierarchical model. To compare RCM with dermoscopy, we grouped studies by population (defined by difficulty of lesion diagnosis) and combined data using hierarchical summary receiver operating characteristic (SROC) methods. Analysis of studies allowing direct comparison between tests was undertaken. To facilitate interpretation of results, we computed values of specificity at the point on the SROC curve with 90% sensitivity as this value lies within the estimates for the majority of analyses. We investigated the impact of using a purposely developed RCM algorithm and in-person test interpretation.

MAIN RESULTS

The search identified 18 publications reporting on 19 study cohorts with 2838 lesions (including 658 with melanoma), which provided 67 datasets for RCM and seven for dermoscopy. Studies were generally at high or unclear risk of bias across almost all domains and of high or unclear concern regarding applicability of the evidence. Selective participant recruitment, lack of blinding of the reference test to the RCM result, and differential verification were particularly problematic. Studies may not be representative of populations eligible for RCM, and test interpretation was often undertaken remotely from the patient and blinded to clinical information.Meta-analysis found RCM to be more accurate than dermoscopy in studies of participants with any lesion suspicious for melanoma and in participants with lesions that were more difficult to diagnose (equivocal lesion populations). Assuming a fixed sensitivity of 90% for both tests, specificities were 82% for RCM and 42% for dermoscopy for any lesion suspicious for melanoma (9 RCM datasets; 1452 lesions and 370 melanomas). For a hypothetical population of 1000 lesions at the median observed melanoma prevalence of 30%, this equated to a reduction in unnecessary excisions with RCM of 280 compared to dermoscopy, with 30 melanomas missed by both tests. For studies in equivocal lesions, specificities of 86% would be observed for RCM and 49% for dermoscopy (7 RCM datasets; 1177 lesions and 180 melanomas). At the median observed melanoma prevalence of 20%, this reduced unnecessary excisions by 296 with RCM compared with dermoscopy, with 20 melanomas missed by both tests. Across all populations, algorithms and thresholds assessed, the sensitivity and specificity of the Pellacani RCM score at a threshold of three or greater were estimated at 92% (95% confidence interval (CI) 87 to 95) for RCM and 72% (95% CI 62 to 81) for dermoscopy.

AUTHORS' CONCLUSIONS

RCM may have a potential role in clinical practice, particularly for the assessment of lesions that are difficult to diagnose using visual inspection and dermoscopy alone, where the evidence suggests that RCM may be both more sensitive and specific in comparison to dermoscopy. Given the paucity of data to allow comparison with dermoscopy, the results presented require further confirmation in prospective studies comparing RCM with dermoscopy in a real-world setting in a representative population.

Reflectance confocal microscopy for diagnosing keratinocyte skin cancers in adults

BACKGROUND

Early accurate detection of all skin cancer types is important to guide appropriate management and improve morbidity and survival. Basal cell carcinoma (BCC) is usually a localised skin cancer but with potential to infiltrate and damage surrounding tissue, whereas cutaneous squamous cell carcinoma (cSCC) and melanoma are higher risk skin cancers with the potential to metastasise and ultimately lead to death. When used in conjunction with clinical or dermoscopic suspicion of malignancy, or both, reflectance confocal microscopy (RCM) may help to identify cancers eligible for non-surgical treatment without the need for a diagnostic biopsy, particularly in people with suspected BCC. Any potential benefit must be balanced against the risk of any misdiagnoses.

OBJECTIVES

To determine the diagnostic accuracy of RCM for the detection of BCC, cSCC, or any skin cancer in adults with any suspicious lesion and lesions that are difficult to diagnose (equivocal); and to compare its accuracy with that of usual practice (visual inspection or dermoscopy, or both).

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists and published systematic review articles.

SELECTION CRITERIA

Studies of any design that evaluated the accuracy of RCM alone, or RCM in comparison to visual inspection or dermoscopy, or both, in adults with lesions suspicious for skin cancer compared with a reference standard of either histological confirmation or clinical follow-up, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data using a standardised data extraction and quality assessment form (based on QUADAS-2). We contacted authors of included studies where information related to the target condition or diagnostic threshold were missing. We estimated summary sensitivities and specificities using the bivariate hierarchical model. For computation of likely numbers of true-positive, false-positive, false-negative, and true-negative findings in the 'Summary of findings' tables, we applied summary sensitivity and specificity estimates to lower quartile, median and upper quartiles of the prevalence observed in the study groups. We also investigated the impact of observer experience.

MAIN RESULTS

The review included 10 studies reporting on 11 study cohorts. All 11 cohorts reported data for the detection of BCC, including 2037 lesions (464 with BCC); and four cohorts reported data for the detection of cSCC, including 834 lesions (71 with cSCC). Only one study also reported data for the detection of BCC or cSCC using dermoscopy, limiting comparisons between RCM and dermoscopy. Studies were at high or unclear risk of bias across almost all methodological quality domains, and were of high or unclear concern regarding applicability of the evidence. Selective participant recruitment, unclear blinding of the reference test, and exclusions due to image quality or technical difficulties were observed. It was unclear whether studies were representative of populations eligible for testing with RCM, and test interpretation was often undertaken using images, remotely from the participant and the interpreter blinded to clinical information that would normally be available in practice.Meta-analysis found RCM to be more sensitive but less specific for the detection of BCC in studies of participants with equivocal lesions (sensitivity 94%, 95% confidence interval (CI) 79% to 98%; specificity 85%, 95% CI 72% to 92%; 3 studies) compared to studies that included any suspicious lesion (sensitivity 76%, 95% CI 45% to 92%; specificity 95%, 95% CI 66% to 99%; 4 studies), although CIs were wide. At the median prevalence of disease of 12.5% observed in studies including any suspicious lesion, applying these results to a hypothetical population of 1000 lesions results in 30 BCCs missed with 44 false-positive results (lesions misdiagnosed as BCCs). At the median prevalence of disease of 15% observed in studies of equivocal lesions, nine BCCs would be missed with 128 false-positive results in a population of 1000 lesions. Across both sets of studies, up to 15% of these false-positive lesions were observed to be melanomas mistaken for BCCs. There was some suggestion of higher sensitivities in studies with more experienced observers. Summary sensitivity and specificity could not be estimated for the detection of cSCC due to paucity of data.

AUTHORS' CONCLUSIONS

There is insufficient evidence for the use of RCM for the diagnosis of BCC or cSCC in either population group. A possible role for RCM in clinical practice is as a tool to avoid diagnostic biopsies in lesions with a relatively high clinical suspicion of BCC. The potential for, and consequences of, misclassification of other skin cancers such as melanoma as BCCs requires further research. Importantly, data are lacking that compare RCM to standard clinical practice (with or without dermoscopy).

Confocal Microscopy in Skin Cancer

Purpose of Review

Reflectance confocal microscopy (RCM) enables imaging of skin lesions at cellular level resolution at the bedside (in vivo) or in freshly excised tissue (ex vivo). This article provides an overview of strengths and limitations of non-invasive RCM in skin cancer diagnosis.

Recent Findings

RCM features of common melanocytic and non-melanocytic skin neoplasms such as melanoma, actinic keratosis/squamous cell carcinoma, basal cell carcinoma, and nevi have been well defined and show good correlation with dermoscopic and histopathologic findings. Due to its technical properties, RCM is especially suitable for the examination of flat skin lesions.

Summary

In vivo RCM has been shown to increase the accuracy of non-invasive diagnosis of common skin neoplasms and is a valuable adjunct to dermoscopy, particularly in cosmetically and functionally sensitive areas such as the face or the genital area.

Reflectance Confocal Microscopy: A Promising Tool to Identify Malignancy in Melanocytic Lesions Exhibiting a Dermoscopic Island

The dermoscopic island is described as a well-defined area in a melanocytic lesion, with a different dermoscopic pattern from the rest of the lesion. It is predictive of melanoma, particularly when the pattern of the island is atypical. We present the reflectance confocal microscopy (RCM) findings in 3 lesions with dermoscopic islands: nevus-associated melanoma, melanocytic nevus, and in situ melanoma. The nevus-associated melanoma and in situ melanoma presented cellular atypia (atypical cells in isolation or forming nests) and architectural distortion on RCM. The nevus presented a dermoscopic island with a typical globular pattern with dense nests and no atypia on RCM. Dermoscopic island is mainly associated with in situ and nevus-associated melanomas. RCM offers good cellular resolution to the depth of the reticular dermis and is useful for diagnosing of melanomas presenting a dermoscopic island.

Brooke-Spiegler syndrome: focus on reflectance confocal microscopy findings of trichoepithelioma and flat cylindroma

Brooke-Spiegler syndrome (BSS) is a rare, autosomal dominant disorder characterized by multiple adnexal tumours, especially trichoepitheliomas, cylindromas and occasionally spiradenomas. These lesions usually begin to appear in the second or third decade of life. Malignant transformation of pre-existing tumours may occur. In vivo reflectance-mode confocal microscopy (RCM) is a noninvasive method that can be used to visualize the epidermis and the upper dermis at almost histological resolution. It has been used to evaluate several skin conditions, especially malignant lesions, and has been reported to be useful for differentiating between malignant and benign skin tumours. Only a few studies have reported on the use of confocal microscopy to characterize the features of benign adnexal neoplasms. We present a patient with BSS who presented to our clinic with multiple skin tumours. The possible utility of RCM for identifying adnexal neoplasms is emphasized in this report, which also describes the observed microscopic features.

Histopathologic and Immunohistochemical Correlates of Confocal Descriptors in Pigmented Facial Macules on Photodamaged Skin

Importance

Pigmented facial macules on photodamaged skin are a clinical, dermoscopic, and histopathologic challenge.

Objectives

To clinically and dermoscopically characterize, by means of reflectance confocal microscopy (RCM), ambiguous pigmented facial macules and establish a correlation between RCM, histopathologic, and immunohistochemical findings.

Design, Setting, and Participants

A prospective study of ambiguous pigmented facial macules on photodamaged skin was conducted in a tertiary referral center for dermatology between January 1, 2009, and December 31, 2015. Sixty-one patients with 63 ambiguous pigmented facial macules and 12 control photodamaged facial areas were included in the study. Melanocyte density in 1-mm basal layers was determined in skin biopsy specimens from all lesions stained with hematoxylin-eosin and immunohistochemical markers (melan-A, microphthalmia-associated transcription factor, and SRY-related HMG-box gene 10). Dermoscopic, RCM images, and histopathologic preparations were systematically evaluated for the presence of lentigo maligna (LM) criteria. Confocal evaluation was blinded to clinical and dermoscopic diagnosis. Sensitivity and specificity of RCM for LM diagnosis and κ value to establish correlations between dermoscopy, RCM, and histopathology were performed.

Main Outcomes and Measures

Sensitivity and specificity of RCM for LM diagnosis.

Results

Of the 61 patients included in the study, 31 (51%) were women; mean (SD) age was 71.8 (13.1) years. Twenty-four of the 63 (38%) lesions were diagnosed as LM or LM melanoma (LMM) and 39 (62%) as benign pigmented lesions. Reflectance confocal microscopy enhanced the diagnosis of pigmented facial macules with 91.7% sensitivity and 86.8% specificity. Multivariate analysis showed 2 dermoscopic and 2 confocal features associated with LM or LMM: (1) asymmetric follicular pigmentation and targetlike structures, and (2) round, large pagetoid cells and follicular localization of atypical cells, respectively. Continuous proliferation of atypical melanocytes was found in 21 (88%) LM or LMM and in 3 (77%) benign lesions. Asymmetric pigmented follicular openings by dermoscopy correlated with follicular localization of pagetoid cells by RCM (κ = 0.499, P < .001). The presence of 3 or more atypical cells at the dermal-epidermal junction (DEJ) by RCM correlated with hyperplasia of melanocytes in hematoxylin-eosin sections (κ = 0.422, P < .001).

Conclusions and Relevance

Reflectance confocal microscopy improves LM diagnosis in photodamaged skin with good histopathologic correlation although false-positive and false-negative cases exist. False-positives obtained with RCM in photodamaged skin are due to the presence of basal melanocyte hyperplasia and intraepidermal Langerhans cells. Histopathologic features of these lesions sometimes are not enough for a definite diagnosis and immunohistochemical studies may be required.

Telediagnosis with Confocal Microscopy: A Reality or a Dream?

Reflectance confocal microscopy (RCM) is becoming more popular among dermatologists aiming to improve their bedside diagnostic accuracy and reduce unnecessary removal of benign cutaneous lesions. With increased interest in the field, limitation of experts, and dedicated training programs, telemedicine application to RCM (teleconfocal) helps to connect patients with experts at a distance. Diagnostic accuracy of store-and-forward telemedicine review of RCM images, patient safety, and cost-effectiveness are important considerations for proper acceptance and usage of the technology in the medical community.

A meta-analysis of reflectance confocal microscopy for the diagnosis of malignant skin tumours

Early diagnosis is extremely important for treatment and prognosis of skin cancer. Reflectance confocal microscopy (RCM) is a recently developed technique used to diagnose skin cancer. This meta-analysis was carried out to assess the accuracy of RCM for the diagnosis of malignant skin tumours. We conducted a systematic literature search of EMBASE, PubMed, the Cochrane Library and Web of Science database for relevant articles in English published up to 24 December 2015. The quality of the included studies was assessed using the QUADAS-2 tool. Statistical analyses were conducted using the software Meta-Disc version 1.4 and STATA version 12.0. A total of 21 studies involving 3108 patients with a total of 3602 lesions were included in the per-lesion analysis. The corresponding pooled results for sensitivity and specificity were 93.6% (95% CI: 0.92-0.95) and 82.7% (95% CI: 0.81-0.84) respectively. Positive likelihood ratio and negative likelihood ratio were 5.84 (95% CI: 4.27-7.98) and 0.08 (95% CI: 0.07-0.10) respectively. Subgroup analysis showed that RCM had a sensitivity of 92.7% (95% CI: 0.90-0.95) and a specificity of 78.3% (95% CI: 0.76-0.81) for detecting melanoma. The pooled sensitivity and specificity of RCM for detecting basal cell carcinoma were 91.7% (95% CI: 0.87-0.95) and 91.3% (95% CI: 0.94-0.96) respectively. RCM is a valid method of identifying malignant skin tumours accurately.

Reflectance confocal microscopy as a second-level examination in skin oncology improves diagnostic accuracy and saves unnecessary excisions: a longitudinal prospective study

BACKGROUND

Dermatoscopy increases both the sensitivity and specificity of melanoma diagnosis. Reflectance confocal microscopy (RCM) is a noninvasive technique that complements dermatoscopy in the evaluation of equivocal lesions at cellular resolution.

OBJECTIVES

To determine prospectively the potential impact of confocal microscopy when implemented in a routine melanoma diagnosis workflow.

METHODS

Patients referred to a single melanoma clinic were consecutively enrolled. At dermatoscopy, patients were referred to one of the following pathways: (i) no further examination or (ii) RCM examination. On examination atypical lesion(s) were referred for either (a) RCM documentation (lesions with consistent suspicious clinical/dermatoscopic criteria, already qualified and scheduled for surgical excision) or (b) RCM consultation for equivocal lesions, where RCM diagnosis would determine lesion definite outcome (excision or digital follow-up).

RESULTS

Reflectance confocal microscopy examination was performed for 41% of 1005 patients enrolled. In two-thirds of these cases RCM influenced the lesion outcome. The systematic application of RCM for equivocal lesions saved over 50% of benign lesions from unnecessary excision. The number needed to excise a melanoma was 6·8 with RCM examination, compared with a hypothetical 14·6 without RCM evaluation.

CONCLUSIONS

Reflectance confocal microscopy as a second-level examination to dermatoscopy proved to be highly accurate in diagnosis and reduced the number of unnecessary excisions. Improved accuracy, considering that RCM enabled the detection of the six melanomas (2%) in the group of 308 lesions eligible for follow-up, also minimizes the risk of referring a melanoma to digital dermatoscopy monitoring, and potentially losing the patient to follow-up.

Surveillance for treatment failure of lentigo maligna with dermoscopy and in vivo confocal microscopy: new descriptors

BACKGROUND

Nonsurgical treatment (radiotherapy, imiquimod) is increasingly employed for the management of lentigo maligna (LM). While the diagnosis of LM remains difficult, the detection of treatment failure is even more challenging.

OBJECTIVES

To describe the sensitivity and specificity for the diagnosis of LM of individual features and methods using dermoscopy and in vivo reflectance confocal microscopy (RCM) to aid in the detection of treatment failure of LM following nonsurgical treatment.

METHODS

A retrospective study of dermoscopy and RCM images (blinded to the correlation with pathology) in patients with biopsy-confirmed LM who were undergoing nonsurgical treatment in two referral institutions - one in Sydney, Australia, and the other in Barcelona, Spain. Ninety-eight patients were treated nonsurgically for LM during the period 2006-2012. Thirty-one patients had abnormal dermoscopy or RCM evaluation, and had a biopsy that identified LM recurrence in 15 patients and nonmelanoma diagnoses in 16 patients (one Bowen disease, 15 solar changes).

RESULTS

The diagnosis of treatment failure was difficult with dermoscopy, with a sensitivity of 80% and specificity of 56%, even with the interpretation of an expert. The best criterion was asymmetric hyperpigmented follicular openings, but this was present in only 47% of treatment failure LM. Isolated, very fine brown dots ('dust' appearance) correlated highly with the diagnosis of treatment failure LM (73% sensitivity and 88% specificity) and with pagetoid cells seen with RCM. The LM score, comprising six criteria, had a specificity of 94% and sensitivity of 100%.

CONCLUSIONS

These methods and descriptors should help to manage the diagnosis of treatment failure.

Role of in vivo reflectance confocal microscopy in determining stability in vitiligo: a preliminary study

BACKGROUND

Vitiligo is an acquired pigmentary disorder. In vivo reflectance confocal microscopy (RCM) reproducible imaging technique has already been reported to be useful in the diagnosis of other skin diseases.

OBJECTIVE

To define RCM features of vitiligo on different clinical stages.

MATERIALS AND METHODS

A total of 125 patients with a clinical diagnosis of vitiligo were included in this study. After informed consent, lesional skins of those vitiligo patients were characterized by using RCM. Five patients with inflammatory cell infiltration observed at the edge of skin lesions and another 5 patients without inflammatory cell infiltration were selected. Biopsies were performed at same sites of the RCM examination areas for histological and immune-histological analysis.

RESULTS

In the active stage of vitiligo, the RCM examination revealed that the bright dermal papillary rings presented at the dermoepidermal junction level in normal skin lost their integrity or totally disappeared, border between vitiligo lesion and normal skin became unclear, and highly refractile cells that referred to infiltrated inflammatory cells could be seen within the papillary dermis at the edge of the lesions. In the stable stage of vitiligo, the RCM showed a complete loss of melanin in lesional skin and a clear border between lesional and normal skin.

CONCLUSION

A simple clinical examination with RCM may reliably and efficiently allow evaluation of the stability status of vitiligo lesions.

Systematic review of diagnostic accuracy of reflectance confocal microscopy for melanoma diagnosis in patients with clinically equivocal skin lesions

BACKGROUND

Melanoma is a cancer of the skin and is increasing in incidence in the UK and Europe. Melanoma is a condition that is often curable if detected at an early stage, which makes accurate diagnosis vital. Reflectance confocal microscopy (RCM) is a tool used to image the skin. It gives high magnification images of the skin, which may provide more accurate diagnosis of lesions that are equivocal on clinical examination and dermoscopy.

OBJECTIVE

To determine the diagnostic accuracy of reflectance confocal microscopy (RCM), for melanoma diagnosis, as an add-on test to clinical examination and dermoscopy in the diagnosis of equivocal pigmented skin lesions using histopathology as the reference standard.

METHODS

A search was conducted of MEDLINE, EMBASE and six other electronic databases from inception to present. Forward citation searching and hand searching of reference lists were also conducted. Diagnostic accuracy studies that assess RCM in the diagnosis of melanoma were included in the review. Two contributors conducted the search, data extraction and assessment of methodological quality using QUADAS-2. Statistical analysis was performed using hierarchical bivariate random effects meta-analysis.

RESULTS

951 titles and abstracts were screened. Five studies comprising 909 lesions were eligible for meta-analysis. Meta-analysis returned a per lesion sensitivity of 93% [95% CI 89-96] and a specificity of 76% [95% CI 68-83].

CONCLUSIONS

The utility of reflectance confocal microscopy (RCM) as an add-on test for the diagnosis of melanoma depends on the trade off between over-excising benign lesions and misdiagnosing melanoma as benign. This becomes important when considering lesions on surgically difficult or cosmetically important areas of the body.

Non-invasive in vivo dermatopathology: identification of reflectance confocal microscopic correlates to specific histological features seen in melanocytic neoplasms

BACKGROUND

Reflectance confocal microscopy (RCM) allows for non-invasive, in vivo evaluation of skin lesions and it has been extensively applied in skin oncology although systematic studies on nevi characterization are still lacking.

OBJECTIVE

The aim of this study was to determine whether reliable RCM correlates to histological features used to diagnose melanocytic neoplasms exist.

METHODS

We blindly evaluated the RCM and histological features of 64 melanocytic neoplasms (19 non-dysplastic nevi, 27 dysplastic nevi, 14 melanomas) and analysed the data using Spearman's rho calculation.

RESULTS

Many histological features can be identified using RCM. Elongated rete ridges corresponded on RCM to edge papillae, whereas flattened rete ridges to several features which involve dermal-epidermal junction disruption. Bridging of junctional nesting (JN) corresponded on RCM to both JN with irregular size/shape and JN with short interconnections. While we could reliably identify dermal melanocytes, the RCM features did not reliably distinguish between benign and concerning dermal melanocytic arrangements, suggesting further refinement of dermal melanocytic RCM features is needed.

CONCLUSION

Reliable correlates for epidermal and junctional histological features used to diagnose melanocytic neoplasms are identifiable on RCM, suggesting harnessing histological criteria may be a reasonable method to move beyond the algorithmic approach.

In vivo confocal microscopy in clinical practice: comparison of bedside diagnostic accuracy of a trained physician and distant diagnosis of an expert reader

BACKGROUND

Reflectance confocal microscopy (RCM) is an imaging tool that allows the visualization of cellular details without biopsy. To our knowledge, RCM sensitivity and specificity has not been studied in a telemedicine setting.

OBJECTIVE

We sought to assess RCM diagnostic accuracy in a support teleconsultation setting.

METHODS

Between June 2010 and September 2011, 340 lesions were imaged using a confocal scanning microscope. The images were evaluated by 2 readers, one on site, and the other at a distance.

RESULTS

A total of 334 cases were included. For each reader the sensitivity was greater than 90% and specificity for each reader was greater than 60%. Both readers had a combined sensitivity of 98.6% and 44% specificity.

LIMITATIONS

RCM may be limited in the correct classification of epithelial tumors.

CONCLUSIONS

RCM is a tool in the clinical diagnosis of skin lesions, providing a high diagnostic accuracy in teleconsultation use.

Clonal seborrheic keratosis: dermoscopic and confocal microscopy characterization

BACKGROUND

The diagnosis of clonal seborrheic keratosis may be challenging clinically and histologically.

OBJECTIVE

In our study, we describe the common aspects of this benign entity that show peculiar dermoscopic and confocal findings.

METHODS

A total of nine clonal seborrheic keratosis were analyzed.

RESULTS

Upon dermoscopy, it reveals the presence of globular-like structures and sharply demarcated borders whereas confocal microscopy displays the typical intraepidermal nesting of pigmented keratinocytes that permits to have a reliable in vivo diagnosis.

CONCLUSIONS

Dermoscopy and confocal microscopy permit to in vivo diagnose this variant of seborrheic keratosis.

Noninvasive in vivo detection and quantification of Demodex mites by confocal laser scanning microscopy

BACKGROUND

In many Demodex-associated skin diseases Demodex mites are present in abundance and seem to be at least partially pathogenic. So far all diagnostic approaches such as scraping or standardized superficial skin biopsy are (semi-)invasive and may cause discomfort to the patient.

OBJECTIVES

To see whether confocal laser scanning microscopy (CLSM) - a noninvasive method for the visualization of superficial skin layers - is able to detect and quantify D. folliculorum in facial skin of patients with rosacea.

METHODS

Twenty-five patients (34-72 years of age) with facial rosacea and 25 age- and sex-matched normal controls were examined by CLSM. Mosaics of 8 × 8 mm and 5 × 5 mm were created by scanning horizontal layers of lesional skin and quantification of mites per follicle and per area as well as follicles per area was performed.

RESULTS

In all patients D. folliculorum could be detected by CLSM and presented as roundish or lengthy cone-shaped structures. CLSM allowed the quantification of Demodex mites and revealed significant differences (P < 0·0001): the mean number of mites was 165·4 per 8 × 8 mm area and 94·2 per 5 × 5 mm area in the patients compared with 34·7 and 22·4, respectively, in the controls. The corresponding mean number of mites per follicle was 0·7 and 0·8, respectively, in the patients and 0·1 and 0·2, respectively, in the controls.

CONCLUSIONS

With the help of CLSM it is possible to detect, image and quantify Demodex mites noninvasively in facial skin of patients with rosacea.

In vivo confocal reflectance microscopy in melanoma

Reflectance confocal microscopy (RCM) enables the noninvasive in vivo imaging of the skin with a horizontal axis and a cellular-level resolution allowing the study of the skin from superficial layers to papillary dermis. It has arisen an important tool in the study of tumors and specially an important role in the characterization of melanoma. Melanocytic lesions present a large number of characteristic findings visible in upper parts of the tumors, such as in the case of melanoma: pagetoid roundish or dendritic cells in superficial epidermis, atypical nests at the dermoepidermal junction, nonedged papillae and atypical nucleated cells in papillary dermis. Several studies have demonstrated that RCM may improve the accuracy in the differentiation of benign and malignant melanocytic lesions as an adjuvant technique to dermoscopy, and three main algorithms have been developed to apply in equivocal lesions. The advantage of in vivo observation in real time of the tumor at the bedside is opening the clinical applications of RCM in the evaluation of melanocytic lesions, and in particular in the study of facial maculae and lentigo maligna melanoma, amelanotic melanoma, and management of subclinical margins, recurrences, or monitoring noninvasive treatment of tumors.

Reflectance confocal microscopy characteristics of eight cases of pustular eruptions and histopathological correlations

BACKGROUND

Reflectance confocal microscopy (RCM)'s interest has been well established for the non-invasive diagnosis of skin cancers, especially melanocytic, and in the differential diagnosis between benign and malignant cutaneous lesions. However, its diagnostic interest in inflammatory skin diseases still needs to be demonstrated. Our purpose was to evaluate the correlation between RCM and conventional histopathology in a series of pustular eruptions of different pathogeny.

METHODS

Reflectance confocal microscopy analysis was performed in eight consecutive unselected patients in whom the diagnoses of pustular psoriasis, bacterial sur-infection, herpes-type virus skin sur-infection, Sneddon-Wilkinson subcorneal putulosis and Hailey-Hailey disease have been made and images were compared to conventional histopathology.

RESULTS

Neutrophils within the epidermis exhibited never reported earlier specific features, with either a shiny granular sludge or polylobated particules with a bright granular content. Moreover, some specific etiologies could be identified, such as acantholysis and herpes-type virus-infected keratinocytes.

CONCLUSION

Our studies show a good correlation between RCM and conventional histopathology in pustular eruptions. Reflectance confocal microscopy may play an important role in the differential diagnosis of pustular eruptions; as most of the pathologic clues are epidermal, narrow thickness of the field of imaging, its main technical limitation, is indeed of lesser importance.

Confocal laser scanning microscopy as a new valuable tool in the diagnosis of onychomycosis - comparison of six diagnostic methods

Onychomycosis is common and can mimic several different nail disorders. Accurate diagnosis is essential to choose the optimum antifungal therapy. The aim of this study was to evaluate the use of confocal laser scanning microscopy (CLSM) and optical coherence tomography (OCT) as new non-invasive diagnostic tools in onychomycosis and to compare them with the established techniques. In a prospective trial, 50 patients with suspected onychomycosis and 10 controls were examined by CLSM and OCT. Parallel KOH preparation, culture, PAS-staining and PCR were performed. PCR showed the highest sensitivity, followed by CLSM, PAS and KOH preparation. OCT offered the second best sensitivity but displayed the lowest specificity. CLSM and KOH preparation showed a high specificity and CLSM offered the best positive predictive value, similar to KOH preparation and OCT. Fungal culture showed the lowest sensitivity and the worst negative predictive value, yet culture and PCR are the only techniques able to identify genus and species. In summary, CLSM was comparable to PAS staining and superior to KOH preparation. Due to the low specificity we assess OCT not as appropriate. In the differentiation of species PCR outplays the fungal culture in terms of time and sensitivity.

Reflectance confocal microscopy accurately discriminates between benign and malignant melanocytic lesions exhibiting a 'dermoscopic island'

BACKGROUND

The 'dermoscopic island' is a term that was recently proposed to design an area of a pigmented lesion with a uniform dermoscopic pattern different from the remainder of the lesion. The positive predictive value of this sign for the diagnosis of melanoma is about 50%.

OBJECTIVE

The purpose of our study was to see if reflectance confocal microscopy (RCM) permitted to accurately distinguish between nevi and melanoma in such lesions.

METHODS

Five lesions of five consecutive unselected patients, with a dermoscopic island but no feasible clear cut diagnosis on the basis of dermoscopy alone were examined by RCM before excision for histopathological evaluation.

RESULTS

Two lesions corresponded to nevi, and three lesions were early melanomas arising on a benign naevus in one case, and on a dysplastic naevus in two cases. In all five cases, RCM permitted to make the correct diagnosis, with a very good correlation with conventional histopathology.

CONCLUSION

Reflectance confocal microscopy appears as a promising tool not only to enhance the early diagnosis of melanoma but also to avoid unnecessary excisions of lesions with a dermoscopic island.

Consistency and distribution of reflectance confocal microscopy features for diagnosis of cutaneous T cell lymphoma

Reflectance confocal microscopy (RCM) represents a noninvasive imaging technique that has previously been used for characterization of mycosis fungoides (MF) in a pilot study. We aimed to test the applicability of RCM for diagnosis and differential diagnosis of MF in a clinical study. A total of 39 test sites of 15 patients with a biopsy-proven diagnosis of either MF, parapsoriasis, Sézary syndrome, or lymphomatoid papulosis were analyzed for presence and absence of RCM features of MF. Cochran and Chi(2) analysis were applied to test the concordance between investigators and the distribution of RCM features, respectively. For selected parameters, the Cochran analysis showed good concordance between investigators. Inter-observer reproducibility was highest for junctional atypical lymphocytes, architectural disarray, and spongiosis. Similarly, Chi(2) analysis demonstrated that selected features were present at particularly high frequency in individual skin diseases, with values ranging from 73% to 100% of all examined cases.