Dermoscopy and Reflectance Confocal Microscopy to Estimate Breslow Index and Mitotic Rate in Primary Melanoma.

Introduction: Non-invasive imaging techniques offer the possibility to optimize the first approach to melanoma. Reflectance Confocal Microscopy (RCM) has a promising role in predicting the main prognostic events in the dermo-epidermal and papillary dermis. Objectives: To identify pre-surgical criteria that can predict the main prognostic features of melanoma. Methods: A retrospective cohort-study evaluated dermoscopic, confocal and histopathological characteristics of consecutively diagnosed sporadic melanomas. RCM-melanoma patterns classified into 1) dendritic-cell, 2) round-cell, 3) dermal nest and 4) combined type. Acral, facial and mucosal locations were excluded. Results: Ninety-two primary melanomas were included: 44 males and 48 females (mean age 60.4 years, standard deviation [SD] 16.2) with a mean Breslow of 1.43 mm (SD 1.6). The most frequent dermoscopic presentation was the multicomponent pattern, the predominant confocal pattern was dendritic-cell type (44.6%). The presence of pigmented network on dermoscopy was related to lower Breslow and mitotic rates (both P = 0.002); in contrast to the presence of visible vessels, which was related to higher Breslow and mitotic indexes (both P = 0.001). Confocal observation of dermal nests or atypical cells in the papillary dermis was related to a higher mitotic rate (P = 0.006 and P = 0.03, respectively). Similarly, diffuse inflammatory infiltrates visible in the superficial dermis was associated with higher Breslow (P = 0.04) and mitotic index (P = 0.04). Conclusions: Dermoscopic and RCM in vivo findings on primary melanoma correlate with histopathologic Breslow index, mitotic rate and tumor infiltrating lymphocytes. The architecture and cytology of primary melanoma can be estimated by combining dermoscopy and RCM prior to excision.

Reflectance Confocal Microscopy and Electrical Impedance Spectroscopy in the Early Detection of Melanoma in Changing Lesions during Long-term Follow-up of Very High-risk Patients.

Electrical impedance spectroscopy has clinical relevance in diagnosing malignancy in melanocytic lesions. Sixty-eight lesions with changes during digital follow-up of patients at very high risk of developing melanoma were prospectively included in this study from February to December 2016. Electrical impedance spectroscopy and reflectance confocal microscopy were performed to evaluate their performance in this subset of difficult lesions. Forty-six lesions were considered suspicious on reflectance confocal microscopy and were excised, of these, 19 were diagnosed as melanoma. Fifteen melanomas were detected by electrical impedance spectroscopy, while 4 received a score lower than 4, which suggested no malignancy. The addition of reflectance confocal microscopy improves accuracy while maintaining the same sensitivity. In the case of electrical impedance spectroscopy scores <4, lesions exhibiting changes in follow-up may need short-term monitoring or excision if dermoscopy shows criteria for melanoma. Results of electrical impedance spectroscopy in this subset of very early lesions should be carefully considered due to the risk of false negatives.

Microblotches on Dermoscopy of Melanocytic Lesions are Associated with Melanoma: A Cross-sectional Study.

Numerous dermoscopic structures for the early detection of melanoma have been described. The aim of this study was to illustrate the characteristics of dermoscopic structures that are similar to blotches, but smaller (termed microblotches), and to evaluate their association with other well-known dermoscopic structures. A cross-sectional study design, including 165 dermoscopic images of melanoma was used to define microblotches, and 241 consecutive images of naevi from the HAM10000 database, were studied to evaluate the prevalence of this criterion in both groups. Microblotches were defined as sharply demarcated structures ≤1 mm, with geographical borders visible only with dermoscopy. Microblotches were present in 38.7% of the melanomas and 6.7% of the naevi. Moreover, microblotches were associated with an odds ratio (OR) of malignancy of 5.79, and were more frequent in invasive melanoma than in the in-situ subtype (OR 2.92). Histologically, they correspond to hyperpigmented parakeratosis or epidermal consumption. In conclusion, microblotches are related to melanomas. This finding could help dermatologists to differentiate between naevi and melanomas.

Improvement of diagnostic confidence and management of equivocal skin lesions by integration of reflectance confocal microscopy in daily practice: Prospective study in 2 referral skin cancer centers.

BACKGROUND: Reflectance confocal microscopy (RCM) allows accurate, noninvasive, in vivo diagnosis for skin cancer. However, its impact on physicians' diagnostic confidence and management is unknown. OBJECTIVES: We sought to assess the physicians' diagnostic confidence and management before and after RCM of equivocal skin lesions. METHODS: Prospective, 2-center, observational study. During clinical practice, 7 dermatologists recorded their diagnostic confidence level (measured in a scale from 0 to 10), diagnosis, and management before and after RCM of clinically/dermoscopically equivocal lesions that raised concern for skin cancer. We also evaluated the diagnostic accuracy before and after RCM. RESULTS: We included 272 consecutive lesions from 226 individuals (mean age, 53.5 years). Diagnostic confidence increased from 6.2 to 8.1 after RCM (P < .001) when RCM confirmed or changed the diagnosis. Lesion management changed in 33.5% cases after RCM (to observation in 51 cases and to biopsy/excision in 31 cases). After RCM, the number needed to excise was 1.2. Sensitivity for malignancy before and after RCM was 78.2% and 85.1%, respectively. Specificity before and after RCM was 78.8% and 80%, respectively. LIMITATIONS: Small sample size, real-life environment, and different levels of expertise among RCM users. CONCLUSION: Physicians' diagnostic confidence and accuracy increased after RCM when evaluating equivocal tumors, frequently resulting in management changes while maintaining high diagnostic accuracy.

Atypical Clinical Presentation of Xeroderma Pigmentosum in a Patient Harboring a Novel Missense Mutation in the XPC Gene: The Importance of Clinical Suspicion.

BACKGROUND: Xeroderma pigmentosum (XP) is a genodermatosis caused by abnormal DNA repair. XP complementation group C (XPC) is the most frequent type in Mediterranean countries. We describe a case with a novel mutation in the XPC gene. CASE: A healthy Caucasian male patient was diagnosed with multiple primary melanomas. Digital follow-up and molecular studies were carried out. RESULTS: During digital follow-up 8 more additional melanomas were diagnosed. Molecular studies did not identify mutations in CDKN2A, CDK4 or MITF genes. Two heterozygous mutations in the XPC gene were detected: c.2287delC (p.Leu763Cysfs*4) frameshift and c.2212A>G (p.Thr738Ala) missense mutations. CONCLUSION: The p.Thr738Ala missense mutation has not been previously described. Missense mutations in the XPC gene may allow partial functionality that could explain this unusual late onset XP. Atypical clinical presentation of XPC could be misdiagnosed when genetic aberrations allow partial DNA repair capacity.