Recurrent pigmented macules after q-switched alexandrite laser treatment of congenital melanocytic nevus

Lentigo maligna melanoma with a history of cosmetic treatment: Prevalence, surgical outcomes and considerations

INTRODUCTION

Lentigo maligna (LM) is melanoma in situ on sun-damaged skin and presents diagnostic challenges due to overlapping features with benign pigmented lesions. Cosmetic treatments may be inadvertently performed on LM. The aim of this study is to estimate the prevalence of LM with prior cosmetic treatment, and evaluate surgical outcomes.

STUDY DESIGN AND METHODS

Retrospective review of biopsy-proven LM presenting over a 10-year-period (2006-2015). Prior cosmetic treatment and biopsies were recorded. Records were reviewed for demographic data, clinical characteristics, and surgical outcomes.

RESULTS

37/503 (7.4%) patients with LM reported prior cosmetic therapy. Most (95%) were on the head and neck; mean size 1.9 cm. Most patients reported cryotherapy (73%), followed by laser (29.7%), topical bleaching agents (18.9%), and electrodessication, and/or curettage (5.3%). Ten patients (27%) received two or more modalities. Eight patients (21.6%) reported prior benign biopsies. Six patients (16%) had invasive disease, two on initial biopsy and 4/34 (11.7%) upstaged upon excision. Average margin for clearance was 9.1 mm.

CONCLUSION

Prior cosmetic treatment of LM is not uncommon, and may delay diagnosis and obscure borders, resulting in wider surgical margins. Clinicians should consider a biopsy confirming the benign nature of equivocal lesions prior to cosmetic treatment. Lasers Surg. Med. 49:819-826, 2017. © 2017 Wiley Periodicals, Inc.

Lasers for nevi: a review

A nevus is described as a benign, often pigmented, skin growth that can be congenital or acquired. Different types of nevi are located at different depths within the skin. Traditional treatments for nevi include topical treatments, dermabrasion, and excision, which are generally ineffective, invasive, and often result in scars and dyspigmentation. Lately, laser therapy has been used as an alternative. Based on the theory of selective photothermolysis, melanin can be specifically targeted, minimizing adverse effects and increasing effectiveness of laser treatments. Several types of lasers and lights have been studied for this purpose without a concise agreement as to which is the best. In general, quality-switched lasers are preferred for the treatment of pigmented lesions. However, there is controversy about this therapy because certain nevi may have malignant potential. This article serves as a comprehensive review of available laser treatments for nevi and discusses the appropriate measures that should be taken before and after laser therapy. Based on the reviewed literature, laser treatment has generally been proven to be a safe and effective therapy for nevi with minimal side effects.

Congenital melanocytic nevi and nevus spilus have a tendency to follow the lines of Blaschko: an examination of 200 cases

There have been few reports about the characteristics of the pigmentary arrangement of congenital melanocytic nevi (CMN) and nevus spilus (NS). Though the lines of Blaschko, which don't correspond to other lines such as Langer's lines and skin dermatomes, are well known to be followed by some rare pigmentary disorders, the relationship between these two disorders and the lines of Blaschko has not been discussed. Therefore, through an examination of 200 cases, we investigated whether or not the arrangement of CMN and NS follow the lines of Blaschko. Thirty-nine out of 92 cases (42.4%) of CMN and 67 out of 108 cases (62.0%) of NS were considered to follow the lines of Blaschko. Today, the idea is widely accepted that two functionally different cells proliferate during early embryogenesis of the skin which is caused from mosaicism and, as a result, the lines of Blaschko appear visually. In our results, we found that there were some cases of CMN and NS which showed a relationship with the lines of Blaschko, which is meaningful considering that the lesions and the lines are both related to pigmentary gene anomalies. The result was compared with CMN and NS by the chi(2) test. NS showed a predominant tendency to follow the lines with a significant difference (P = 0.0055). This may indicate that the lines of Blaschko reflect more clearly the proliferation of the epidermal cells than other cells in growth of the skin of the embryo. Further studies are required to elucidate the reason why some cases follow these lines and others do not.