Dermoscopic Features of Melanocytic Nevi in Cardiofaciocutaneous and Costello Syndromes.

Importance: Somatic variants in the RAS/MAPK pathway genes are commonly associated with melanocytic nevi and melanoma, whereas germline variants in these genes are associated with RASopathies, syndromes involving multiple organs, including the skin. Nevi counts may be higher in some RASopathies, but studies on features observed through dermoscopy are limited. Objective: To determine the distinguishing dermoscopic features of melanocytic nevi and how the RAS pathway influences them by comparing nevi in patients with cardiofaciocutaneous syndrome (CFC) and Costello syndrome (CS). Design, Setting, and Participants: In this prospective cohort study, patients with CFC and CS, 2 RASopathies caused by variants in the downstream and upstream components of the RAS/MAPK pathway, were recruited from the international CFC and CS family conferences. Some patients with CFC also elected to participate in a longitudinal follow-up study. Main Outcomes and Measures: The main outcomes were dermoscopic features and, in the longitudinal follow-up study, nevi counts, which were recorded over time. Results: A total of 39 patients, 16 with CFC and 23 with CS, were enrolled (overall cohort: 26 [66.7%] female; median [IQR] age, 13.0 [7.6-22.0] years). The 112 nevi overall frequently displayed an organized dermoscopic pattern (CFC, 61 [84.7%]; CS, 34 [85.0%]) rather than a disorganized pattern (CFC, 6 [8.3%]; CS, 1 [2.5%]). Of the organized nevi, homogenous brown was the most common pattern (CFC, 41 [67.2%]; CS, 22 [64.7%]), followed by reticular (CFC, 11 [18.0%]; CS, 7 [20.6%]) and globular (CFC, 9 [14.8%]; CS, 5 [14.7%]). Pigmented networks occurred in 12 nevi in CFC (16.7%) and 6 nevi in CS (15%; P > .99). Of these, 6 CFC-associated nevi (50%) and no CS-associated nevi had atypical networks (P = .05). Six patients with CFC in the follow-up study developed significantly more nevi within 5 years (median [IQR] increase, 24.5 [10-120] nevi; P = .04). Conclusions and Relevance: In this cohort study, the findings suggest that nevi in patients with CFC and CS commonly display organized homogenous brown dermoscopic patterns, and the number of nevi may significantly increase over time in those with CFC. A disorganized pattern and atypical networks may be more frequent in patients with CFC. Future studies are needed to determine the risk of melanoma in individuals with CFC or CS.

Acquired Melanocytic Nevi Mimicking Acral Lentiginous Melanoma in a Patient Taking a BRAF Inhibitor.

This case report describes a patient in their 60s with metastatic colon cancer who developed multiple new dark nevi within 2 months of initiating encorafenib and panitumumab therapy.

Prospective validation of dermoscopy-based open-source artificial intelligence for melanoma diagnosis (PROVE-AI study).

The use of artificial intelligence (AI) has the potential to improve the assessment of lesions suspicious of melanoma, but few clinical studies have been conducted. We validated the accuracy of an open-source, non-commercial AI algorithm for melanoma diagnosis and assessed its potential impact on dermatologist decision-making. We conducted a prospective, observational clinical study to assess the diagnostic accuracy of the AI algorithm (ADAE) in predicting melanoma from dermoscopy skin lesion images. The primary aim was to assess the reliability of ADAE's sensitivity at a predefined threshold of 95%. Patients who had consented for a skin biopsy to exclude melanoma were eligible. Dermatologists also estimated the probability of melanoma and indicated management choices before and after real-time exposure to ADAE scores. All lesions underwent biopsy. Four hundred thirty-five participants were enrolled and contributed 603 lesions (95 melanomas). Participants had a mean age of 59 years, 54% were female, and 96% were White individuals. At the predetermined 95% sensitivity threshold, ADAE had a sensitivity of 96.8% (95% CI: 91.1-98.9%) and specificity of 37.4% (95% CI: 33.3-41.7%). The dermatologists' ability to assess melanoma risk significantly improved after ADAE exposure (AUC 0.7798 vs. 0.8161, p = 0.042). Post-ADAE dermatologist decisions also had equivalent or higher net benefit compared to biopsying all lesions. We validated the accuracy of an open-source melanoma AI algorithm and showed its theoretical potential for improving dermatology experts' ability to evaluate lesions suspicious of melanoma. Larger randomized trials are needed to fully evaluate the potential of adopting this AI algorithm into clinical workflows.

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.

Ancillary techniques to improve dermoscopy specificity for skin cancer detection.

Although the use of dermoscopy has markedly improved both the sensitivity and specificity for skin cancer detection, there is still opportunity for improvement. Ancillary techniques provide additional ways to assess a lesion with the aim of improving our diagnostic ability with little extra cost. Usage of these techniques can strengthen diagnosis and help reduce unnecessary biopsies of benign lesions.