Criterios Dermatoscópicos para Melanoma

Accuracy of Dermoscopic Criteria for the Diagnosis of Melanoma in Situ

JAMA dermatology (Chicago, Ill.)

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• The authors assessed the accuracy of known melanoma dermoscopic features used to diagnose melanoma in situ (MIS) in this multicenter study. A total of five dermoscopic findings were associated with MIS: atypical network (OR, 3.7); regression >50% (OR, 4.7); irregular hyperpigmented areas (OR, 5.4); angulated lines (OR, 2.2); and prominent skin markings (OR, 3.4). Irregular hyperpigmented areas and prominent skin markings differentiated MIS from atypical nevi. A multicomponent global pattern and blue–white veil favored a diagnosis of invasive melanoma over MIS, and extensive regression indicated MIS over invasive melanoma.

• The results would suggest that clinicians must consider the dermoscopic criteria and markers when diagnosing MIS.

  – Anna A. Wile, MD

 Dermatology

Written by

 

 

George Han MD, PhD

Dermoscopy is now widely used among dermatologists to aid in the diagnosis of pigmented lesions, and criteria for invasive melanoma have been validated and widely accepted. However, when these criteria were applied to melanoma-in-situ, the diagnostic accuracy was much lower. This multicenter study examined over 1200 lesions and correlated histologic diagnoses with dermoscopic evaluations from 3 dermatologists experienced in dermoscopy. The ultimate analysis concluded that, although atypical nevi and melanoma-in-situ share several features, namely regression, an atypical network, and irregular dots/globules, melanoma-in-situ exhibited three features that were more common vs atypical nevi. Those three findings are irregular hyperpigmented areas, prominent skin markings, and angulated lines.

Meanwhile, a multicomponent global pattern and blue–white veil were more indicative of invasive melanoma rather than melanoma-in-situ. This study thus revealed two new, previously undescribed, indicators for melanoma-in-situ. Irregular hyperpigmented areas, the most strongly associated finding with melanoma-in-situ, are small, bizarrely shaped dark brown/black areas in the central portion of a pigmented lesion. Prominent skin markings represent intersecting linear furrows, lighter than the color of the rest of the lesion. Together, these new indicators of melanoma-in-situ may help dermatologists diagnose a melanoma at an earlier, in-situ, stage, allowing for successful excision and, potentially, a complete cure.

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Abstract

IMPORTANCE

The accuracy of melanoma-specific dermoscopic criteria has been tested mainly in studies including invasive tumors. Scarce evidence exists on the usefulness of these criteria for the diagnosis of melanoma in situ (MIS).

OBJECTIVE

To investigate the diagnostic accuracy of dermoscopic criteria for the diagnosis of MIS.

DESIGN, SETTING, AND PARTICIPANTS

A diagnostic accuracy study with retrospective patient enrollment was conducted in 3 centers specializing in skin cancer diagnosis and management. A total of 1285 individuals with histopathologically diagnosed MIS or other flat, pigmented skin tumors that were histopathologically diagnosed or monitored for at least 1 year were included. Dermoscopic images of MIS and other flat, pigmented skin tumors were evaluated by 3 independent investigators for the presence of predefined criteria. Evaluators were blinded to the clinic dermoscopic and histopathologic diagnosis.

MAIN OUTCOMES AND MEASURES

Frequencies of dermoscopic criteria per diagnosis were calculated. Crude odds ratios, adjusted odds ratios, and corresponding 95% CIs were calculated by univariate and multivariate logistic regression, respectively.

RESULTS

A total of 1285 patients were included in the study (642 [50%] male); mean age was 45.9 years (range, 9-91 years). Of a total of 1285 lesions obtained from these patients, 325 (25.3%) were MIS; 574 (44.7%) were nevi (312 [24.3%] excised and 262 [20.4%] not excised); 67 (5.2%) were seborrheic keratoses, solar lentigines, or lichen planus-like keratoses; 91 (7.1%) were pigmented superficial basal cell carcinomas; 26 (2.0%) were pigmented intraepithelial carcinomas; 100 (7.8%) were Reed nevi; and 102 (7.9%) were invasive melanomas with a Breslow thickness less than 0.75 mm. The most frequent dermoscopic criteria for MIS were regression (302 [92.9%]), atypical network (278 [85.5%]), and irregular dots and/or globules (163 [50.2%]). The multivariate analysis revealed 5 main positive dermoscopic indicators of MIS: atypical network (3.7-fold; 95% CI, 2.5-5.4), regression (4.7-fold; 95% CI, 2.8-8.1), irregular hyperpigmented areas (5.4-fold; 95% CI, 3.7-8.0), prominent skin markings (3.4-fold; 95% CI, 1.9-6.1), and angulated lines (2.2-fold; 95% CI, 1.2-4.1). When compared only with excised nevi, 2 of these criteria remained potent MIS indicators, namely, irregular hyperpigmented areas (4.3-fold; 95% CI, 2.7-6.8) and prominent skin markings (2.7-fold; 95% CI, 1.3-5.7).

CONCLUSIONS AND RELEVANCE

Clinicians should take into consideration the aforementioned dermoscopic indicators for the diagnosis of MIS.

Copyright © 2018 Elsevier Inc. All rights reserved.

Additional Info

• Article Citation

JAMA dermatology (Chicago, Ill.)

Accuracy of Dermoscopic Criteria for the Diagnosis of Melanoma in Situ

JAMA Dermatol 2018 Feb 21;[EPub Ahead of Print], A Lallas, C Longo, M Manfredini, E Benati, G Babino, C Chinazzo, Z Apalla, C Papageorgiou, E Moscarella, A Kyrgidis, G Argenziano