International Skin Imaging Collaboration-Designated Diagnoses (ISIC-DX): Consensus terminology for lesion diagnostic labeling

BACKGROUND

A common terminology for diagnosis is critically important for clinical communication, education, research and artificial intelligence. Prevailing lexicons are limited in fully representing skin neoplasms.

OBJECTIVES

To achieve expert consensus on diagnostic terms for skin neoplasms and their hierarchical mapping.

METHODS

Diagnostic terms were extracted from textbooks, publications and extant diagnostic codes. Terms were hierarchically mapped to super-categories (e.g. 'benign') and cellular/tissue-differentiation categories (e.g. 'melanocytic'), and appended with pertinent-modifiers and synonyms. These terms were evaluated using a modified-Delphi consensus approach. Experts from the International-Skin-Imaging-Collaboration (ISIC) were surveyed on agreement with terms and their hierarchical mapping; they could suggest modifying, deleting or adding terms. Consensus threshold was >75% for the initial rounds and >50% for the final round.

RESULTS

Eighteen experts completed all Delphi rounds. Of 379 terms, 356 (94%) reached consensus in round one. Eleven of 226 (5%) benign-category terms, 6/140 (4%) malignant-category terms and 6/13 (46%) indeterminate-category terms did not reach initial agreement. Following three rounds, final consensus consisted of 362 terms mapped to 3 super-categories and 41 cellular/tissue-differentiation categories.

CONCLUSIONS

We have created, agreed upon, and made public a taxonomy for skin neoplasms and their hierarchical mapping. Further study will be needed to evaluate the utility and completeness of the lexicon.

Diagnosis of invasive cutaneous squamous cell carcinoma, imaging and staging

The assessment of patients with a lesion raising the suspicion of an invasive cutaneous squamous cell carcinoma (cSCC) is a frequent clinical scenario. The management of patients with cSCC is a multistep approach, starting with the correct diagnosis. The two main diagnostic goals are to differentiate from other possible diagnoses and correctly recognize the lesion as cSCC, and then to determine the tumor spread (perform staging), that is if the patient has a common primary cSCC or a locally advanced cSCC, or a metastatic cSCC (with in-transit, regional lymph nodal, or rarely distant metastasis). The multistep diagnostic approach begins with the clinical characteristics of the primary cSCC, it is complemented with features with dermoscopy and, if available, reflectance confocal microscopy and is confirmed with histopathology. The tumor spread is assessed by physical examination and, in some cases, ultrasound and/or computed tomography or magnetic resonance imaging, mainly to investigate for regional lymph node metastasis or for local infiltration into deeper structures. In the last step, the clinical, histologic and radiologic findings are incorporated into staging systems.

Expert Agreement on the Presence and Spatial Localization of Melanocytic Features in Dermoscopy

Dermoscopy aids in melanoma detection; however, agreement on dermoscopic features, including those of high clinical relevance, remains poor. In this study, we attempted to evaluate agreement among experts on exemplar images not only for the presence of melanocytic-specific features but also for spatial localization. This was a cross-sectional, multicenter, observational study. Dermoscopy images exhibiting at least 1 of 31 melanocytic-specific features were submitted by 25 world experts as exemplars. Using a web-based platform that allows for image markup of specific contrast-defined regions (superpixels), 20 expert readers annotated 248 dermoscopic images in collections of 62 images. Each collection was reviewed by five independent readers. A total of 4,507 feature observations were performed. Good-to-excellent agreement was found for 14 of 31 features (45.2%), with eight achieving excellent agreement (Gwet's AC >0.75) and seven of them being melanoma-specific features. These features were peppering/granularity (0.91), shiny white streaks (0.89), typical pigment network (0.83), blotch irregular (0.82), negative network (0.81), irregular globules (0.78), dotted vessels (0.77), and blue-whitish veil (0.76). By utilizing an exemplar dataset, a good-to-excellent agreement was found for 14 features that have previously been shown useful in discriminating nevi from melanoma. All images are public (www.isic-archive.com) and can be used for education, scientific communication, and machine learning experiments.

Use of Dermoscopy among Greek Dermatologists in Everyday Clinical Practice: A National Questionnaire-Based Study

Background: Dermatoscopy has been established as an important diagnostic tool for a wide range of skin diseases. This study aims to evaluate the use of dermatoscopy in clinical practice among Greek dermatologists. Methods: A nationwide questionnaire-based survey was conducted collecting data on the frequency of dermatoscopic examinations, the types of lesions examined, training and educational resources, as well as factors influencing the choice to incorporate dermatoscopy into daily clinical routines. Results: A total of 366 Greek dermatologists participated in the survey. Most of the respondents reported the daily use of dermatoscopy in their practice. Pigmented and non-pigmented lesions, inflammatory diseases, cutaneous infectious, hair disorders, and nail lesions were the most common indications for dermatoscopy. Factors influencing the utilization of dermatoscopy included increased diagnostic accuracy, enhanced patient care, better patient communication and general compliance, and improved satisfaction among dermatologists. Conclusions: This national questionnaire-based study demonstrates that dermatoscopy has become an integral part of daily dermatological practice in Greece. The findings highlight the significance of structured training and education to promote dermoscopy's effective and routine use. Incorporating dermatoscopy into clinical practice not only improves diagnostic precision but also enhances patient care, contributing to the overall quality of dermatological services in Greece.

Perifollicular linear projections: A dermatoscopic criterion for the diagnosis of lentigo maligna on the face

BACKGROUND

Lentigo maligna (LM) can mimic benign, flat, pigmented lesions and can be challenging to diagnose.

OBJECTIVE

To describe a new dermatoscopic feature termed "perifollicular linear projections (PLP)" as a diagnostic criterion for LM on the face.

METHODS

Retrospective study on reflectance confocal microscopy and dermatoscopy images of flat facial pigmented lesions originating from 2 databases. PLP were defined as short, linear, pigmented projections emanating from hair follicles. Dermatoscopy readers were blinded to the final histopathologic diagnosis.

RESULTS

From 83 consecutive LMs, 21/83 (25.3%) displayed "bulging of hair follicles" on reflectance confocal microscopy and 18 of these 21 (85.7%), displayed PLP on dermatoscopy. From a database of 2873 consecutively imaged and biopsied lesions, 252 flat-pigmented facial lesions were included. PLP was seen in 47/76 melanomas (61.8%), compared with 7/176 lesions (3.9%) with other diagnosis (P < .001). The sensitivity was 61.8% (95% CI, 49.9%-72.7%), specificity 96.0% (95% CI, 92.9%-98.4%). PLP was independently associated with LM diagnosis on multivariate analysis (OR 26.1 [95% CI, 9.6%-71.0]).

LIMITATIONS

Retrospective study.

CONCLUSION

PLP is a newly described dermatoscopic criterion that may add specificity and sensitivity to the early diagnosis of LM located on the face. We postulate that PLP constitutes an intermediary step in the LM progression model.

Seven Plus One Steps to Assess Pigmented Nail Bands (Melanonychia Striata Longitudinalis)

Melanonychia striata longitudinalis might involve one or more fingers and/or toes and might result from several different causes, including benign and malignant tumors, trauma, infections, and activation of melanocytes that might be reactive or related to the pigmentary trait, drugs and some rare syndromes. This broad differential diagnosis renders the clinical assessment of melanonychia striata particularly challenging. Nail matrix melanoma is relatively rare, occurs almost always in adults involves more frequently the first toe or thumb. The most common nail unit cancer, squamous cell carcinoma / Bowen disease (SCC) of the nail matrix is seldom pigmented. Histopathologic examination remains the gold standard for melanoma and SCC diagnosis, but excisional or partial biopsies from the nail matrix require training and is not routinely performed by the majority of clinicians. Furthermore, the histopathologic evaluation of melanocytic lesions of the nail matrix is particularly challenging, since early melanoma has only bland histopathologic alterations. Dermatoscopy of the nail plate and its free edge significantly improves the clinical diagnosis, since specific patterns have been associated to each one of the causes of melanonychia. Based on knowledge generated and published in the last decades, we propose herein a stepwise diagnostic approach for melanonychia striata longitudinalis: 1) Hemorrhage first 2) Age matters 3) Number of nails matters 4) Free edge matters 5) Brown or gray? 6) Size matters 7) Regular or irregular and, finally, "follow back".

Paradoxical effect of epinephrine on lesion redness and vascularity

INTRODUCTION

Epinephrine is commonly used in combination with local anesthetic (lidocaine/epinephrine) due to its beneficial vasoconstrictive properties. Typically, pallor is appreciated after injection as a sign of effect; however, we observed that some cutaneous malignancies paradoxically revealed increased redness and vascularity after injection of lidocaine/epinephrine. In this study, we investigate this phenomenon among a series of biopsied lesions to identify characteristics of lesions associated with increased redness and/or vascularity.

OBJECTIVES

To determine characteristics of lesions which become redder or more vascular after injection with lidocaine/epinephrine prior to biopsy.

METHODS

This cross-sectional study consisted of a convenience sample of lesions scheduled for biopsy. Lesions were photographed prior to and 7 min after injection of lidocaine/epinephrine as a part of standard care. Two readers blinded to study objectives and histopathological diagnosis assessed lesions for changes in redness and vascular features.

RESULTS

Fifty-four lesions from 47 patients-61.7% male, mean age 64.8 years, age-range 24-91 were included. Thirty-six lesions were biopsy confirmed malignant, with 5 in situ and 31 invasive malignancies; the remaining 18 lesions were benign. In comparison with non-malignant lesions, malignant lesions were associated with an increase in clinically appreciable vascular features after injection of lidocaine/epinephrine, X2 (1) = 21.600, p < 0.001. Further stratification into benign, in situ, and invasive lesions strengthened the association, X2 (1) = 23.272, p < 0.001.

CONCLUSIONS

Combination lidocaine/epinephrine has been shown to paradoxically increase the visibility of vessels seen in cutaneous malignancies. This is consistent with prior literature suggesting aberrant adrenergic signaling in neoangiogenic vessels.

The Natural Evolution of Nevi with Peripheral Globules

BACKGROUND

Peripheral globules (PG) in melanocytic lesions represent a concerning dermoscopic feature since they might be present in growing nevi and melanomas. Their natural evolution has not been fully elucidated, and an age-based management approach has been recommended.

OBJECTIVES

The aim of this study was to calculate the growth rate of lesions with PG and investigate possible association with age, sex, location, and the global dermoscopic pattern.

METHODS

We retrospectively selected the lesions of interest from a cohort of Caucasian patients who underwent sequential digital dermoscopy monitoring. Lesions with PG distributed at 75% or more of their circumference with available follow-up images or histopathologic report were included. The surface area was automatically calculated with the help of an incorporated tool used in the acquisition of the images. The images were also evaluated by independent investigators for the presence of pre-defined criteria. Growth-curve models were used to assess the growth rate. The outcome variable was the area of nevi in mm2, and scatterplots with Lowess curves were used to present the mean change of nevi during follow-up.

RESULTS

A total of 208 lesions from 98 patients with a median age of 36 years (range 15-75) were included. The median follow-up time was 18 months (range 4-48). The mean growth rate for all nevi was 0.16 mm2/month (95% CI, 0.14-0.18, p < 0.001), ranging from -0.29 to 0.61 mm2/month. The growth rate was higher in nevi with a homogeneous dermoscopic pattern (p < 0.001). The number of peripheral globules during follow-up varied from increasing to complete disappearance. None of the lesions developed any melanoma-specific structure at follow-up.

CONCLUSION

Nevi with PG grew at a mean rate of 0.16 mm2/month, and the growth rate was independent of age, gender, or anatomic location. Nevi with homogeneous pattern demonstrated the highest growth rate in our cohort. None of the monitored nevi with PG developed melanoma-specific criteria at follow-up.

Clinical and Dermoscopic Characteristics of Cutaneous Sarcomas: A Literature Review

Under the umbrella of cutaneous sarcomas (CS) we include a heterogeneous group of rare, malignant, mesenchymal neoplasia, such as dermatofibrosarcoma protuberans, atypical fibroxanthoma, cutaneous undifferentiated pleomorphic sarcoma, cutaneous angiosarcoma and leiomyosarcoma. Clinical presentation and histopathological examination are the cornerstone of CS diagnosis and classification. There are scarce data in the literature in regards to the clinical and dermatoscopic characteristics of CS and the role of dermatoscopy in their early identification. We performed a literature review, aiming to summarize current data on the clinical and dermatoscopic presentation of the most common types of cutaneous sarcomas that may facilitate early diagnosis and prompt management. Based on the available published data, CS are characterized by mostly unspecific dermatoscopic patterns. Dermatofibrosarcoma protuberans, Kaposi's sarcoma, and in a lesser degree, cutaneous angiosarcoma, may display distinct dermatoscopic features, facilitating their early clinical recognition. In conclusion, dermatoscopy, in conjunction with the overall clinical context, may aid towards suspicion of CS.

Eccrine Porocarcinoma: A Review of the Literature

Eccrine porocarcinoma (EPC) constitutes a rare malignant adnexal tumor, which accounts for about 0.005-0.01% of all cutaneous malignancies. It may develop de novo or arise from an eccrine poroma, after a latency period of years or even decades. Accumulating data suggest that specific oncogenic drivers and signaling pathways may be implicated in its tumorigenesis, while recent data have demonstrated a high overall mutation rate attributed to UV exposure. Diagnosis may be challenging and should rely on the combination of clinical, dermoscopical, histopathological and immunohistochemical findings. The literature is controversial regarding tumor behavior and prognosis and, therefore, there is no consensus on its surgical management, utility of lymph-node biopsy and further adjuvant or systemic treatment. However, recent advances in tumorigenesis of EPC may aid in the development of novel treatment strategies, which could improve survival of advanced or metastatic disease, such as immunotherapy. This review presents an update of the epidemiology, pathogenesis and clinical presentation of EPC and summarizes current data on diagnostic evaluation and management of this rare cutaneous malignancy.

Lentigo maligna melanoma mapping using reflectance confocal microscopy correlates with staged excision: A prospective study

BACKGROUND

Lentigo maligna/lentigo maligna melanoma (LM/LMM) can present with subclinical extension that may be difficult to define preoperatively and lead to incomplete excision and potential recurrence. Preliminarily studies have used reflectance confocal microscopy (RCM) to assess LM/LMM margins.

OBJECTIVE

To evaluate the correlation of LM/LMM subclinical extension defined by RCM compared with the gold standard histopathology.

METHODS

Prospective study of LM/LMM patients referred for dermatologic surgery. RCM was performed at the clinically defined initial surgical margin followed by margin-controlled staged excision with paraffin-embedded tissue, and histopathology was correlated with RCM results.

RESULTS

Seventy-two patients were included. Mean age was 66.8 years (standard deviation, 11.1; range, 38-89); 69.4% were men. Seventy of 72 lesions (97.2%) were located on the head and neck with mean largest clinical diameter of 1.3 cm (range, 0.3-5). Diagnostic accuracy for detection of residual melanoma in the tumor debulk (after biopsy) had a sensitivity of 96.7% and a specificity of 66.7% when compared with histopathology. RCM margin assessment revealed an overall agreement with final histopathology of 85.9% (κ = 0.71; P < .001).

LIMITATIONS

No RCM imaging beyond initial planned margins was performed.

CONCLUSION

RCM showed moderate to excellent overall agreement between RCM imaging of LM/LMM and histopathology of staged excision margins.

Dermoscopy of Actinic Keratosis: Is There a True Differentiation between Non-Pigmented and Pigmented Lesions?

Dermoscopic features of actinic keratosis (AK) have been widely studied, but there is still little evidence for their diagnostic accuracy. Our study investigates whether established dermoscopic criteria are reliable predictors in differentiating non-pigmented actinic keratosis (NPAK) from pigmented actinic keratosis (PAK). For this purpose, dermoscopic images of 83 clinically diagnosed AK (45 NPAK, 38PAK) were examined, and the sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) were assessed. Features with statistical significance were the red pseudo-network (p = 0.02) for NPAK and the pigmented pseudo-network (p < 0.001) with a pigment intensity value even less than 10% for PAK (p = 0.001). Pigmented pseudo-network (Se: 89%, Sp: 77%, PPV: 77%, NPV: 89%) with a pigment intensity value of more than 10% (Se: 90%, Sp: 86%, PPV: 79%, NPV: 93%) had excellent diagnostic accuracy for PAK. Scale and widened follicular openings with yellowish dots surrounded by white circles were equally represented in both variants of AK. Linear wavy vessels and shiny streaks were more prominently observed in NPAK, as were rosettes in PAK, but these results failed to meet statistical significance. The red starburst pattern was near statistical significance for PAK. Therefore, pigmentation is the strongest dermoscopic predictor for the differentiation between NPAK and PAK.

Agreement Between Experts and an Untrained Crowd for Identifying Dermoscopic Features Using a Gamified App: Reader Feasibility Study

BACKGROUND

Dermoscopy is commonly used for the evaluation of pigmented lesions, but agreement between experts for identification of dermoscopic structures is known to be relatively poor. Expert labeling of medical data is a bottleneck in the development of machine learning (ML) tools, and crowdsourcing has been demonstrated as a cost- and time-efficient method for the annotation of medical images.

OBJECTIVE

The aim of this study is to demonstrate that crowdsourcing can be used to label basic dermoscopic structures from images of pigmented lesions with similar reliability to a group of experts.

METHODS

First, we obtained labels of 248 images of melanocytic lesions with 31 dermoscopic "subfeatures" labeled by 20 dermoscopy experts. These were then collapsed into 6 dermoscopic "superfeatures" based on structural similarity, due to low interrater reliability (IRR): dots, globules, lines, network structures, regression structures, and vessels. These images were then used as the gold standard for the crowd study. The commercial platform DiagnosUs was used to obtain annotations from a nonexpert crowd for the presence or absence of the 6 superfeatures in each of the 248 images. We replicated this methodology with a group of 7 dermatologists to allow direct comparison with the nonexpert crowd. The Cohen κ value was used to measure agreement across raters.

RESULTS

In total, we obtained 139,731 ratings of the 6 dermoscopic superfeatures from the crowd. There was relatively lower agreement for the identification of dots and globules (the median κ values were 0.526 and 0.395, respectively), whereas network structures and vessels showed the highest agreement (the median κ values were 0.581 and 0.798, respectively). This pattern was also seen among the expert raters, who had median κ values of 0.483 and 0.517 for dots and globules, respectively, and 0.758 and 0.790 for network structures and vessels. The median κ values between nonexperts and thresholded average-expert readers were 0.709 for dots, 0.719 for globules, 0.714 for lines, 0.838 for network structures, 0.818 for regression structures, and 0.728 for vessels.

CONCLUSIONS

This study confirmed that IRR for different dermoscopic features varied among a group of experts; a similar pattern was observed in a nonexpert crowd. There was good or excellent agreement for each of the 6 superfeatures between the crowd and the experts, highlighting the similar reliability of the crowd for labeling dermoscopic images. This confirms the feasibility and dependability of using crowdsourcing as a scalable solution to annotate large sets of dermoscopic images, with several potential clinical and educational applications, including the development of novel, explainable ML tools.

Artificial Intelligence in Dermatology: Challenges and Perspectives

Artificial intelligence (AI) based on machine learning and convolutional neuron networks (CNN) is rapidly becoming a realistic prospect in dermatology. Non-melanoma skin cancer is the most common cancer worldwide and melanoma is one of the deadliest forms of cancer. Dermoscopy has improved physicians' diagnostic accuracy for skin cancer recognition but unfortunately it remains comparatively low. AI could provide invaluable aid in the early evaluation and diagnosis of skin cancer. In the last decade, there has been a breakthrough in new research and publications in the field of AI. Studies have shown that CNN algorithms can classify skin lesions from dermoscopic images with superior or at least equivalent performance compared to clinicians. Even though AI algorithms have shown very promising results for the diagnosis of skin cancer in reader studies, their generalizability and applicability in everyday clinical practice remain elusive. Herein we attempted to summarize the potential pitfalls and challenges of AI that were underlined in reader studies and pinpoint strategies to overcome limitations in future studies. Finally, we tried to analyze the advantages and opportunities that lay ahead for a better future for dermatology and patients, with the potential use of AI in our practices.

Dermoscopy of Linear Basal Cell Carcinomas, a Potential Mimicker of Linear Lesions: a Descriptive Case-series

Introduction

Among the various widely recognized basal cell carcinoma (BCC) clinical patterns, linear basal cell carcinoma (LBCC) is an uncommon morphologic variant of BCC.

Objectives

Describe the clinical and dermoscopic characteristics of LBCC.

Methods

Retrospective study including LBCC cases from 5 dermatology centers in North and South America. Biopsy-proven primary BCCs, that presented with at least 3:1 length:width ratio on physical examination, irrespective of tumor subtype or location, were included. Clinical and dermoscopic analysis were performed by 2 experts in dermoscopy.

Results

Eighteen cases of LBCC met our inclusion criteria and were included in the study. Median age at diagnosis was 86.0 years, 10 patients (58.8%) were males. Regarding anatomic location, 11/18 (61.1%) were located on the head and neck, 5/18 (27.7%) cases were found on the trunk, and 2 on lower extremities (11.1%). Under dermoscopy, 15/18 (83.3%) of LBCC were pigmented. All tumors displayed at least one of the BCC-specific dermoscopic criteria the most common being blue-grey globules (72.2%).

Conclusions

Dermoscopy might be useful in the differentiation of LBCC from other diagnoses presenting as linear lesions such as scars, scratches/erosions, and tattoos, among others. Some of these lesions might be confused by naked eye examination alone.

The degradation of performance of a state-of-the-art skin image classifier when applied to patient-driven internet search

Model Dermatology ( https://modelderm.com ; Build2021) is a publicly testable neural network that can classify 184 skin disorders. We aimed to investigate whether our algorithm can classify clinical images of an Internet community along with tertiary care center datasets. Consecutive images from an Internet skin cancer community ('RD' dataset, 1,282 images posted between 25 January 2020 to 30 July 2021; https://reddit.com/r/melanoma ) were analyzed retrospectively, along with hospital datasets (Edinburgh dataset, 1,300 images; SNU dataset, 2,101 images; TeleDerm dataset, 340 consecutive images). The algorithm's performance was equivalent to that of dermatologists in the curated clinical datasets (Edinburgh and SNU datasets). However, its performance deteriorated in the RD and TeleDerm datasets because of insufficient image quality and the presence of out-of-distribution disorders, respectively. For the RD dataset, the algorithm's Top-1/3 accuracy (39.2%/67.2%) and AUC (0.800) were equivalent to that of general physicians (36.8%/52.9%). It was more accurate than that of the laypersons using random Internet searches (19.2%/24.4%). The Top-1/3 accuracy was affected by inadequate image quality (adequate = 43.2%/71.3% versus inadequate = 32.9%/60.8%), whereas participant performance did not deteriorate (adequate = 35.8%/52.7% vs. inadequate = 38.4%/53.3%). In this report, the algorithm performance was significantly affected by the change of the intended settings, which implies that AI algorithms at dermatologist-level, in-distribution setting, may not be able to show the same level of performance in with out-of-distribution settings.

Checklist for Evaluation of Image-Based Artificial Intelligence Reports in Dermatology: CLEAR Derm Consensus Guidelines From the International Skin Imaging Collaboration Artificial Intelligence Working Group

IMPORTANCE

The use of artificial intelligence (AI) is accelerating in all aspects of medicine and has the potential to transform clinical care and dermatology workflows. However, to develop image-based algorithms for dermatology applications, comprehensive criteria establishing development and performance evaluation standards are required to ensure product fairness, reliability, and safety.

OBJECTIVE

To consolidate limited existing literature with expert opinion to guide developers and reviewers of dermatology AI.

EVIDENCE REVIEW

In this consensus statement, the 19 members of the International Skin Imaging Collaboration AI working group volunteered to provide a consensus statement. A systematic PubMed search was performed of English-language articles published between December 1, 2008, and August 24, 2021, for "artificial intelligence" and "reporting guidelines," as well as other pertinent studies identified by the expert panel. Factors that were viewed as critical to AI development and performance evaluation were included and underwent 2 rounds of electronic discussion to achieve consensus.

FINDINGS

A checklist of items was developed that outlines best practices of image-based AI development and assessment in dermatology.

CONCLUSIONS AND RELEVANCE

Clinically effective AI needs to be fair, reliable, and safe; this checklist of best practices will help both developers and reviewers achieve this goal.

Deep Learning for Basal Cell Carcinoma Detection for Reflectance Confocal Microscopy

Basal cell carcinoma (BCC) is the most common skin cancer, with over 2 million cases diagnosed annually in the United States. Conventionally, BCC is diagnosed by naked eye examination and dermoscopy. Suspicious lesions are either removed or biopsied for histopathological confirmation, thus lowering the specificity of noninvasive BCC diagnosis. Recently, reflectance confocal microscopy, a noninvasive diagnostic technique that can image skin lesions at cellular level resolution, has shown to improve specificity in BCC diagnosis and reduced the number needed to biopsy by 2-3 times. In this study, we developed and evaluated a deep learning-based artificial intelligence model to automatically detect BCC in reflectance confocal microscopy images. The proposed model achieved an area under the curve for the receiver operator characteristic curve of 89.7% (stack level) and 88.3% (lesion level), a performance on par with that of reflectance confocal microscopy experts. Furthermore, the model achieved an area under the curve of 86.1% on a held-out test set from international collaborators, demonstrating the reproducibility and generalizability of the proposed automated diagnostic approach. These results provide a clear indication that the clinical deployment of decision support systems for the detection of BCC in reflectance confocal microscopy images has the potential for optimizing the evaluation and diagnosis of patients with skin cancer.

Clinical and dermatoscopic predictors of squamous cell carcinoma of the lips: a case-control, multicentric study

BACKGROUND

Squamous cell carcinoma of the lip accounts for 20% of all oral carcinomas. Its diagnosis may be challenging because it clinically resembles actinic cheilitis and inflammatory lesions of the lips.

OBJECTIVES

To determine clinical and dermatoscopic predictors of squamous cell carcinoma of the lip vs. other lip lesions.

METHODS

Multicentre retrospective morphological study, including histologically confirmed cases of squamous cell carcinoma of the lip and controls consisting of actinic cheilitis and inflammatory lesions of the lips. Clinical and dermatoscopic images were evaluated for the presence of predefined criteria. Crude and adjusted odds ratios and corresponding 95% confidence intervals were calculated by univariate and multivariate logistic regression respectively.

RESULTS

A total of 177 lip lesions were evaluated, 107 (60.5%) were squamous cell carcinomas and 70 (39.5%) were controls. The most frequent dermatoscopic criteria of lip squamous cell carcinoma were scales (100%), white halos (87.3%) and ulceration (79.4%). The majority of squamous cell carcinomas displayed polymorphic vessels (60.8%), with linear (68.6%) and hairpin (67.6%) being the most frequent types. Multivariate logistic regression analysis showed that clinical predictors of lip squamous cell carcinoma were exophytic appearance and clinical hyperkeratosis, with 43-fold and 6-fold higher probability respectively. White clods and ulceration in dermoscopy presented a 6-fold and 4-fold increased risk for squamous cell carcinoma respectively.

CONCLUSIONS

A scaly lesion with exophytic growth, dermatoscopically displaying white clods, ulceration and linear and hairpin vessels is very likely a squamous cell carcinoma of the lip.

Optical imaging guided- 'precision' biopsy of skin tumors: a novel approach for targeted sampling and histopathologic correlation

Dermoscopy and reflectance confocal microscopy (RCM) are two noninvasive, optical imaging tools used to facilitate clinical diagnosis. A biopsy technique that produces exact correlation with optical imaging features is not previously reported. To evaluate the applications of a novel feature-focused 'precision biopsy' technique that correlates clinical-dermoscopy-RCM findings with histopathology. This was a prospective case-series performed during August 2017 and June 2019 at a tertiary care cancer. We included consecutive patients requiring a precise dermoscopy-RCM-histopathologic correlation. We performed prebiopsy dermoscopy and both wide probe and handheld RCM of suspicious lesions. Features of interest were isolated with the aid of paper rings and a 2 mm punch biopsy was performed in the dermoscopy- or RCM-highlighted area. Tissue was processed either en face or with vertical sections. One-to-one correlation with histopathology was obtained. Twenty-three patients with 24 lesions were included in the study. The mean age was 64.6 years (range 22-91 years); there were 16 (69.6%) males, 14 (58.3%) lesions biopsied were on head and neck region. We achieved tissue-conservation diagnosis in 100% (24/24), 13 (54.2%) were clinically equivocal lesions, six (25%) were selected for 'feature correlation' of structures on dermoscopy or RCM, and five (20.8%) for 'correlation of new/unknown' RCM features seen on follow-up. The precision biopsy technique described herein is a novel method that facilitates direct histopathological correlation of dermoscopy and RCM features. With the aids of optical imaging devices, accurate diagnosis may be achieved by minimally invasive tissue extraction.

Bilateral diffuse uveal melanocytic proliferation with multifocal diffuse integumentary melanocytic proliferation paraneoplastic syndrome: A case report

Bilateral diffuse uveal melanocytic proliferation (B-DUMP) is a rare paraneoplastic syndrome typically presenting with bilateral visual loss. B-DUMP is associated with extraocular systemic malignancies with the most common being lung cancer in males and uro-gynaecological cancer in females (mainly ovarian cancer). Cutaneous and/or mucosal involvement in patients with B-DUMP has been reported but it is not well characterised. Herein, we present a female in her 70s with diagnosis of stage IV vaginal clear-cell carcinoma and metastatic melanoma of unknown primary that developed progressive bilateral loss of visual acuity compatible with 'B-DUMP'. Simultaneously, she developed multifocal bilateral bluish-greyish patches on the skin that were shown to have a proliferation of dermal melanocytes. We propose that the clinical and histopathologic cutaneous findings seen in patients with B-DUMP be termed 'diffuse integumentary melanocytic proliferation (DIMP)'.

Incidence of New Primary Cutaneous Melanoma in Patients With Metastatic Melanoma Treated With Immune Checkpoint Inhibitors: A Single-Center Cohort Study

Importance

The development of new primary cutaneous melanoma (CM) after starting immune checkpoint inhibitor (ICI) therapy is poorly characterized.

Objective

To determine the incidence of new CM in patients treated with ipilimumab, nivolumab, and/or pembrolizumab for metastatic melanoma.

Design, Setting, and Participants

Single-center, retrospective, observational cohort study using an institutional database to identify patients diagnosed with melanoma at a tertiary care cancer hospital in New York, New York.

Exposures

Ipilimumab, nivolumab, and/or pembrolizumab treatment for metastatic melanoma.

Main Outcomes and Measures

Primary outcomes were the incidence proportion, the incidence rate, and the 5-year cause-specific cumulative risk.

Results

A total of 2251 patients were included in the study; mean (SD) age at the time of ICI start was 62.8 (14.4) years. The majority were male (63.8%, n = 1437), White (92.7%, n = 2086), and non-Hispanic (92.1%, n = 2073). Forty-two of 2251 patients who received ipilimumab, nivolumab, and/or pembrolizumab were diagnosed with 48 new CMs at a median (range) of 397.5 (39-2409) days after ICI initiation. The median age of affected patients at the time of ICI first dose was 66.5 years. The majority were male (66.7%, n = 28), White (92.9%, n = 39), and non-Hispanic (100.0%, n = 42). There were no differences in age, sex, race, and ethnicity among patients who did and did not develop a new CM. Patients who developed a new CM were more likely to have a family history of melanoma (23.8% vs 16.3%, P = .02). Most new CMs (n = 30, 62.5%) were diagnosed after the last date of ICI administration. Twenty-seven (56.3%) new CMs were in situ and 21 (43.8%) were invasive. Of the invasive CMs with a reported Breslow thickness (n = 20), the median (range) thickness was 0.4 (0.1-8.4) mm. The overall incidence proportion of new CM was 1.9% (95% CI, 1.4%-2.5%) and the incidence rate was 1103 cases per 100 000 person-years (95% CI, 815-1492). The 5-year cumulative cause-specific risk of new CM was 4.9% (95% CI, 3.3%-7.4%).

Conclusions and Relevance

Patients treated with ICI therapy for metastatic melanoma remain at risk for the development of new CM.

Association of Multiple Aggregated Yellow-White Globules With Nonpigmented Basal Cell Carcinoma

Importance

Basal cell carcinoma (BCC) is the most common skin cancer. Dermoscopic imaging has improved diagnostic accuracy; however, diagnosis of nonpigmented BCC remains limited to arborizing vessels, ulceration, and shiny white structures.

Objective

To assess multiple aggregated yellow-white (MAY) globules as a diagnostic feature for BCC.

Design, Setting, and Participants

In this retrospective, single-center, case-control study, nonpigmented skin tumors, determined clinically, were identified from a database of lesions consecutively biopsied during a 7-year period (January 1, 2009, to December 31, 2015). A subset of tumors was prospectively diagnosed, and reflectance confocal microscopy, optical coherence tomography, and histopathologic correlation were performed. Data analysis was conducted from July 1 to September 31, 2019.

Exposures

Investigators evaluated for the presence or absence of known dermoscopic criteria. MAY globules were defined as aggregated, white-yellow structures visualized in polarized and nonpolarized light.

Main Outcomes and Measures

The primary outcome was the diagnostic accuracy of MAY globules for the diagnosis of BCC. Secondary objectives included the association with BCC location and subtype. Interrater agreement was estimated.

Results

A total of 656 nonpigmented lesions from 643 patients (mean [SD] age, 63.1 [14.9] years; 381 [58.1%] male) were included. In all, 194 lesions (29.6%) were located on the head and neck. A total of 291 (44.4%) were BCCs. MAY globules were seen in 61 of 291 BCC cases (21.0%) and in 3 of 365 other diagnoses (0.8%) (P < .001). The odds ratio for diagnosis of BCC was 32.0 (96% CI, 9.9-103.2). The presence of MAY globules was associated with a diagnosis of histologic high-risk BCC (odds ratio, 6.5; 95% CI, 3.1-14.3). The structure was never seen in cases of superficial BCCs.

Conclusions and Relevance

The findings suggest that MAY globules may have utility as a new BCC dermoscopic criterion with a high specificity. MAY globules were negatively associated with superficial BCC and positively associated with deeper-seated, histologic, higher-grade tumor subtypes.

Dermatoscopy of melanoma according to type, anatomic site and stage

The indisputable contribution of dermatoscopy in early diagnosis of melanoma is widely recognized. In the last quinquennium, new data concerning specific melanoma subtypes have come to light. The dermatoscopic morphology of superficial spreading melanoma (SSM) has been extensively investigated in the literature. Atypical network, irregular dots, irregular globules, irregular streaks and irregular blotch correspond to histopathologic alterations at the level of the junction, blue-white veil and atypical vessels suggest intradermal growth, whereas regression structures, negative network and white shiny streaks might reflect junctional or dermal alterations. The list of melanoma specific criteria has been recently updated to include features that typify early melanoma, such as irregular hyperpigmented areas and prominent skin markings and features seen in melanoma on sun damaged skin such as angulated lines. Nodular melanoma lacks most of the aforementioned criteria and is typified by the coexistence of blue and black color, atypical vessels and pink color. Lentigo maligna dermatoscopic criteria mainly develop at the outline of the follicular openings. However, at an early stage these features might be very subtle and the diagnosis should be based on the exclusion of benign tumors (inverse approach). Acral lentiginous melanoma is typified by a parallel ridge pattern, but also SSM criteria should be taken into consideration. The diagnosis of subungual melanoma is based on the assessment of the color and characteristics of the pigmented nail band. For the diagnosis of mucosal melanoma, the assessment of colors is more informative than the assessment of structures and the detection of blue, white or gray should raise the suspicion of melanoma. White shiny streaks and regression structures are the most common features of desmoplastic melanoma. The diagnosis of nevoid melanoma might be highly challenging and require information on the lesion's history. Melanoma on small- and medium-sized congenital nevi is typified by an eccentric location of the suspicious area, negative network and gray angulated lines. Recent advances in knowledge on the dermatoscopic characteristics of peculiar subtypes of the tumor significantly enrich the diagnostic armamentarium of clinicians. The challenge of the forthcoming years is to better characterize biologically aggressive melanomas and to optimize the screening strategies so as to identify them.

Performance of a deep neural network in teledermatology: a single-centre prospective diagnostic study

BACKGROUND

The use of artificial intelligence (AI) algorithms for the diagnosis of skin diseases has shown promise in experimental settings but has not been yet tested in real-life conditions.

OBJECTIVE

To assess the diagnostic performance and potential clinical utility of a 174-multiclass AI algorithm in a real-life telemedicine setting.

METHODS

Prospective, diagnostic accuracy study including consecutive patients who submitted images for teledermatology evaluation. The treating dermatologist chose a single image to upload to a web application during teleconsultation. A follow-up reader study including nine healthcare providers (3 dermatologists, 3 dermatology residents and 3 general practitioners) was performed.

RESULTS

A total of 340 cases from 281 patients met study inclusion criteria. The mean (SD) age of patients was 33.7 (17.5) years; 63% (n = 177) were female. Exposure to the AI algorithm results was considered useful in 11.8% of visits (n = 40) and the teledermatologist correctly modified the real-time diagnosis in 0.6% (n = 2) of cases. The overall top-1 accuracy of the algorithm (41.2%) was lower than that of the dermatologists (60.1%), residents (57.8%) and general practitioners (49.3%) (all comparisons P < 0.05, in the reader study). When the analysis was limited to the diagnoses on which the algorithm had been explicitly trained, the balanced top-1 accuracy of the algorithm (47.6%) was comparable to the dermatologists (49.7%) and residents (47.7%) but superior to the general practitioners (39.7%; P = 0.049). Algorithm performance was associated with patient skin type and image quality.

CONCLUSIONS

A 174-disease class AI algorithm appears to be a promising tool in the triage and evaluation of lesions with patient-taken photographs via telemedicine.

The dermatoscopic spectrum of cutaneous lupus erythematosus: A retrospective analysis by clinical subtype with clinicopathological correlation

The skin is the most common organ of involvement during the course of lupus erythematosus (LE). The literature data concerning the dermatoscopic patterns of the different clinical variants of cutaneous LE (CLE), namely chronic (CCLE), subacute (SCLE), and acute (ACLE), are scarce. To determine the dermatoscopic spectrum of CLE and to correlate the dermatoscopic features with the histological findings. This was a retrospective, observational, multicenter, cohort study. We evaluated the dermatoscopic features in a cohort of patients diagnosed with CLE. Furthermore, we investigated their frequency per clinical subtype and correlated them with the anatomic alterations. We included 79 patients. The most prevalent dermatoscopic features of CCLE included follicular plugs (86.4%, P < .01), patchy distribution (75%, P = .1) of mostly linear curved vessels (56.8%, P = .8), white scales (68.2%, P < .01), and structureless white color (68.2%, P < .01). The most common criteria of SCLE were patchy distribution (90%, P = .1) of mostly linear curved vessels (53.3%, P = .8) and fine white scales (60%, P < .01), while ACLE was characterized by erythema (100%, P < .05) and patchy distribution (100%, P = .1) of mostly dotted vessels (60%, P = .4). Follicular plugs/rosettes in dermatoscopy strongly correlated with follicular plugs in histology (rho = 0.919). Hyperkeratosis significantly correlated with white (rho = 0.644) and yellow/brown scales (rho = 0.225), telangiectasia with linear curved vessels (rho = 0.321) and white color with dermal fibrosis (rho = 0.623). Depending on CLE subtype, distinct dermatoscopic patterns are recognized. In CLE there is a high correlation between certain dermatoscopic criteria and the underneath anatomic alteration.

Incompletely excised lentigo maligna melanoma is associated with unpredictable residual disease: clinical features and the emerging role of reflectance confocal microscopy

BACKGROUND

Lentigo maligna/lentigo maligna melanoma (LM/LMM) poses a treatment and surgical challenge given unpredictable subclinical extension resulting in incomplete excision.

OBJECTIVES

To describe the demographic, clinical and pathologic characteristics of incompletely excised LM/LMM. To evaluate the potential role of reflectance confocal microscopy (RCM).

PATIENTS AND METHODS

A retrospective review of a melanoma database at a tertiary cancer centre for patients referred with 'incompletely excised LM/LMM' or 'incompletely excised melanoma' between October 2006 and July 2017. We recorded clinical and pathological data and surgical margins needed to clear the residual LM/LMM. The second part consisted of a prospective cohort of patients in which RCM was performed when presenting with incompletely excised LM/LMM.

RESULTS

We included a total of 67 patients (retrospective + prospective cohort); mean age was 64.9 (standard deviation: 11.3) years and 52.2% were males. For the retrospective cohort (n = 53), the mean scar size was 3.4 cm. The average initial margins excised prior to presentation were 4.8 mm (range 3-7 mm). The average additional margin needed to clear the residual, incompletely excised LM/LMM was 7.8 mm. For the prospective cohort (n = 14), there were no differences in age, gender or size when compared to the retrospective cohort. RCM had a diagnostic accuracy of 78.6%, a sensitivity of 90.9%, a specificity of 33.3% and a positive predictive value of 83.3% for the detection of incompletely excised LM/LMM.

CONCLUSIONS

Incompletely excised LM/LMM is a poorly characterized clinical-pathological scenario that may require considerable extra margins for microscopic clearance. RCM may emerge as a valuable tool for the evaluation of patients with incompletely excised LM/LMM.

Human surface anatomy terminology for dermatology: a Delphi consensus from the International Skin Imaging Collaboration

BACKGROUND

There is no internationally vetted set of anatomic terms to describe human surface anatomy.

OBJECTIVE

To establish expert consensus on a standardized set of terms that describe clinically relevant human surface anatomy.

METHODS

We conducted a Delphi consensus on surface anatomy terminology between July 2017 and July 2019. The initial survey included 385 anatomic terms, organized in seven levels of hierarchy. If agreement exceeded the 75% established threshold, the term was considered 'accepted' and included in the final list. Terms added by the participants were passed on to the next round of consensus. Terms with <75% agreement were included in subsequent surveys along with alternative terms proposed by participants until agreement was reached on all terms.

RESULTS

The Delphi included 21 participants. We found consensus (≥75% agreement) on 361/385 (93.8%) terms and eliminated one term in the first round. Of 49 new terms suggested by participants, 45 were added via consensus. To adjust for a recently published International Classification of Diseases-Surface Topography list of terms, a third survey including 111 discrepant terms was sent to participants. Finally, a total of 513 terms reached agreement via the Delphi method.

CONCLUSIONS

We have established a set of 513 clinically relevant terms for denoting human surface anatomy, towards the use of standardized terminology in dermatologic documentation.

Dermatoscopic features of thin (≤2 mm Breslow thickness) vs. thick (>2 mm Breslow thickness) nodular melanoma and predictors of nodular melanoma versus nodular non-melanoma tumours: a multicentric collaborative study by the International Dermoscopy Society

BACKGROUND

Thin nodular melanoma (NM) often lacks conspicuous melanoma-specific dermatoscopic criteria and escapes clinical detection until it progresses to a thicker and more advanced tumour.

OBJECTIVE

To investigate the dermatoscopic morphology of thin (≤2 mm Breslow thickness) vs. thick (>2 mm) NM and to identify dermatoscopic predictors of its differential diagnosis from other nodular tumours.

METHODS

Retrospective, morphological case-control study, conducted on behalf of the International Dermoscopy Society. Dermatoscopic images of NM and other nodular tumours from 19 skin cancer centres worldwide were collected and analysed.

RESULTS

Overall, 254 tumours were collected (69 NM of Breslow thickness ≤2 mm, 96 NM >2 mm and 89 non-melanoma nodular lesions). Light brown coloration (50.7%) and irregular brown dots/globules (42.0%) were most frequently observed in ≤2 mm NMs. Multivariate analysis revealed that dotted vessels (3.4-fold), white shiny streaks (2.9-fold) and irregular blue structureless area (2.4-fold) were predictors for thinner NM compared to non-melanoma nodular tumours. Overall, irregular blue structureless area (3.4-fold), dotted vessels (4.6-fold) and serpentine vessels (1.9-fold) were predictors of all NM compared to non-melanoma nodular lesions.

LIMITATIONS

Absence of a centralized, consensus pathology review and cases selected form tertiary centres maybe not reflecting the broader community.

CONCLUSIONS

Our study sheds light into the dermatoscopic morphology of thin NM in comparison to thicker NM and could provide useful clues for its differential diagnosis from other non-melanoma nodular tumours.

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.

Dermoscopy: A Review of the Structures That Facilitate Melanoma Detection

Melanoma is currently the fifth most common cancer in the United States, resulting in more than 9000 deaths each year. Despite numerous improvements in the management of advanced melanoma, the cornerstone to ensuring a cure remains early detection. Both patient and physician awareness regarding the signs and symptoms of early melanoma remain paramount. As a result, much effort has been and continues to be expended in developing and refining effective diagnostic algorithms to help identify melanomas and differentiate them from nevi, such as the ABCDE rule (A for asymmetry, B for border irregularity, C for color variegation, D for diameter >6 mm, and E for evolution in lesion size, shape, or color). To assist in the detection of more subtle melanomas requires technology to augment a visual examination. Toward this end, a simple instrument called a dermatoscope has transformed not only the appreciation of the morphology of melanoma but also its growth dynamics. The discipline of dermoscopy has improved the detection of melanoma and other skin cancers, has resulted in the detection of thinner melanomas, and has helped improve the ability to differentiate nevi (benign lesions) from melanomas, which, in turn, has resulted in fewer biopsies of benign lesions. Since patients often first present to their primary care physicians for their health-related concerns, it is imperative that primary care physicians be able to recognize the lesions that are suspicious for melanoma. This review is intended to introduce osteopathic physicians to the dermoscopic features associated primarily with melanomas located on nonglabrous skin.

Management of complex head-and-neck basal cell carcinomas using a combined reflectance confocal microscopy/optical coherence tomography: a descriptive study

INTRODUCTION

Recently, a combined reflectance confocal microscopy (RCM)-optical coherence tomography (OCT) has been tested for the diagnosis of basal cell carcinoma (BCC). Evaluating the role of RCM-OCT in management of complex BCCs has not been studied. The objective of the study was to investigate the utility of a new combined RCM-OCT device in the evaluation and management of complex BCCs in a descriptive study.

METHODS

Prospective study of consecutive cases (July 2018-June 2019) of biopsy-proven 'complex' BCC defined as BCC in the head-and-neck area with multiple high-risk criteria such as large size in the mask area, multiple recurrences, and high-risk subtype. All cases were evaluated with a combined RCM-OCT device that provided simultaneous image viewing on a screen. Lesions were evaluated bedside with RCM-OCT according to previously described criteria.

RESULTS

Ten patients with complex head-and-neck BCCs had mean age of 73.1 ± 13.0 years. Six (60%) patients were males. Mean BCC clinical size was 1.9 ± 1.2 cm (range 0.6-4.0 cm). RCM detected residual BCC in 8 out of 10 cases (80%) and OCT detected residual BCC in all 10 cases (100%). Six BCCs (60%) had a depth estimate of > 1000 µm under OCT. In five cases, (50%) RCM-OCT imaging results led to a change/modification in BCC management.

CONCLUSION

The use of a combined RCM-OCT device may help in the evaluation of complex head-and-neck BCCs by guiding treatment selection and defining the extent of surgery.

Reflectance confocal microscopy and dermoscopy aid in evaluating repigmentation within or adjacent to lentigo maligna melanoma surgical scars

BACKGROUND

Determining whether repigmentation within or adjacent to lentigo maligna or lentigo maligna melanoma (LM/LMM) scars represents recurrence of melanoma is challenging. The use of reflectance confocal microscopy (RCM) and dermoscopy may aid in differentiating true melanoma recurrence from other causes of repigmentation.

OBJECTIVES

To describe the characteristics of repigmentation within or adjacent to LM/LMM scars observable on RCM and dermoscopy.

METHODS

We retrospectively analysed patients who presented with new pigmentation within or adjacent to scars from surgically treated LM/LMM between January 2014 and December 2018. Clinical and demographic characteristics and time to recurrence were recorded. RCM was used to evaluate areas of pigmentation before biopsy. If available, dermoscopic images were also evaluated.

RESULTS

In total, 30 confocal studies in 29 patients were included in the study cohort. Twenty-one patients had biopsy-confirmed recurrent LM/LMM; the remainder had pigmented actinic keratosis (n = 4) or hyperpigmentation/solar lentigo (n = 5). RCM had sensitivity of 95.24% (95% CI, 76.18-99.88%), specificity of 77.7% (95% CI, 39.99-97.19%), positive predictive value of 90.91% (95% CI, 74.58-97.15%) and negative predictive value of 87.5% (95% CI, 50.04-98.0%). The most common dermoscopic feature observed among patients with recurrent LM/LMM was focal homogeneous or structureless areas of light-brown pigmentation (92.8% vs. 37.5% in patients with other diagnoses; P = 0.009). LM-specific dermoscopic criteria were present in only 28.5% of patients with recurrent LM/LMM.

CONCLUSIONS

Reflectance confocal microscopy and dermoscopy are valuable tools for the comprehensive evaluation of repigmentation within or adjacent to LM scars.

Reflectance confocal microscopy confirms residual basal cell carcinoma on clinically negative biopsy sites before Mohs micrographic surgery: A prospective study

BACKGROUND

Biopsy specimens from patients with basal cell carcinoma (BCC) can present to surgery with no clinically residual tumor, complicating treatment decisions.

OBJECTIVE

To evaluate reflectance confocal microscopy (RCM) for the assessment of residual BCC following biopsy.

METHODS

Consecutive patients with biopsy-proven BCC and no clinical evidence of residual tumor who had been referred for Mohs micrographic surgery were included. Biopsy sites were imaged with a handheld RCM device. On the basis of RCM evaluation, cases were labeled RCM positive or RCM negative. Mohs micrographic surgery was performed in all cases; margins and 15-μm serial vertical sectioning were evaluated.

RESULTS

A total of 61 patients were included (mean age, 61.7 years [standard deviation, 12.2 years]; range, 37-87 years); 60.7% were women. The mean lesion size was 5.1 mm (range, 3-12 mm); 73.8% of patients were positive on RCM, and 68.9% had residual BCC on histopathologic examination. The rates of RCM sensitivity, specificity, positive predictive value, and negative predictive value were 92.8%, 68.4%, 86.6%, and 81.2%, respectively. Three cases of BCC (high-risk, infiltrative, and basosquamous) were missed with use of RCM. When high-risk subtypes were excluded (n = 5), sensitivity and negative predictive value were both 100%.

LIMITATIONS

RCM can miss deep-seated residual tumor.

CONCLUSION

RCM is a valuable tool for the evaluation of residual BCC following biopsy, with the potential to reduce unnecessary surgical procedures.

Reflectance confocal microscopy-guided carbon dioxide laser ablation of low-risk basal cell carcinomas: A prospective study

BACKGROUND

Basal cell carcinoma (BCC) treatment modalities can be stratified by tumor subtype and recurrence risk. The main limitation of nonsurgical treatment modalities is the lack of histopathologic confirmation. Reflectance confocal microscopy (RCM) is a noninvasive imaging device that provides quasihistologic images.

OBJECTIVE

To evaluate the feasibility and efficacy of RCM-guided carbon dioxide (CO₂) laser ablation of low-risk BCCs.

METHODS

Prospective study with biopsy specimen-proven low-risk BCCs imaged with RCM. RCM was performed on these sites before and after ablation. If residual tumor was found, a new series of laser passes were performed. The patients were then monitored for recurrence clinically and with RCM.

RESULTS

Twenty-two tumor sites in 9 patients (5 men, 4 women) were imaged and treated. Median age was 59 ± 12.9 years (range, 30-74 years). Mean tumor size was 7.7 mm (range, 5-10 mm). Residual tumor was identified in 5 of 22 cases (22.7%) under RCM on immediate first-pass postablation sites, prompting additional laser passes. Median follow-up was 28.5 months (range, 22-32 months) with no recurrences found.

CONCLUSIONS

Addition of RCM to laser ablation workflow can detect subclinical persistent tumor after initial ablation and may serve as an aid to increase the efficacy of laser ablation.

Clinical and dermoscopic features associated with lichen planus-like keratoses that undergo skin biopsy: A single-center, observational study

BACKGROUND/OBJECTIVES

Lichen planus-like keratoses (LPLK) are benign skin lesions that can mimic malignancy; the clinical and dermoscopic features distinguishing lichen planus-like keratoses from skin tumors have not been extensively studied. The objective of this study was to identify dermoscopic features that may prevent unnecessary biopsies of lichen planus-like keratoses.

METHODS

Retrospective, single-center, observational study of biopsied skin lesions at a tertiary center. We compared 355 lichen planus-like keratoses to 118 non-lichen planus-like keratoses lesions with lichen planus-like keratosis in the differential diagnosis biopsied from August 1, 2015, to December 31, 2016. The investigators were blinded to the diagnosis of the lesions.

RESULTS

Lichen planus-like keratoses were most frequently non-pigmented (61.7%), truncal (52.1%), and on sun-damaged skin (69.6%); the majority occurred in Whites (95.5%) and females (62.8%). Dermoscopically, lichen planus-like keratoses were more likely than non-lichen planus-like keratoses to have scale (42.5% vs 31.4%, P = 0.03) and orange colour (8.2% vs 0.9%, P = 0.01). Among lesions with peppering (n = 76; 63 lichen planus-like keratoses and 13 non-lichen planus-like keratoses), coarse ± fine peppering (73% vs 38.5%, P = 0.02) and peppering as the only feature (34.9% vs 0%, P = 0.01) were associated with lichen planus-like keratoses.

CONCLUSIONS

Lichen planus-like keratoses can be challenging to distinguish from benign and malignant skin tumors. The presence of dermoscopic scale and orange colour may aid in the recognition of lichen planus-like keratosis. Coarse peppering and the presence of peppering as the only dermoscopic feature may further aid the identification of pigmented lichen planus-like keratoses.