Lentigines, laser, and melanoma: a case series and discussion

Lentigo maligna and lentigo maligna melanoma in patients younger than 50 years: a multicentre international clinical-dermoscopic study

BACKGROUND

Lentigo maligna/lentigo maligna melanoma (LM/LMM) is usually diagnosed in older patients, when lesions are larger. However, it is important to detect it at an earlier stage to minimize the area for surgical procedure.

OBJECTIVES

To determine and define clinical, dermoscopic and reflectance confocal microscopy (RCM) features of LM/LMM in patients < 50 years old.

METHODS

This was a multicentre study involving tertiary referral centres for skin cancer management. The study included cases of consecutively excised LM/LMM arising in patients < 50 years of age with a histopathological diagnosis of LM/LMM and a complete set of clinical and dermoscopic images; RCM images were considered when present.

RESULTS

In total, 85 LM/LMM of the face from 85 patients < 50 years were included in the study. A regression model showed a direct association with the size of the lesion (R2 = 0.08; P = 0.01) and with the number of dermoscopic features at diagnosis (R2 = 0.12; P < 0.01). In a multivariable analysis, an increasing number of dermoscopic features correlated with increased patient age (P < 0.01), while the presence of grey colour was a predictor of younger age at diagnosis (P = 0.03). RCM revealed the presence of melanoma diagnostic features in all cases (pagetoid cells and atypical nesting).

CONCLUSIONS

LM is not a disease limited to older people as previously thought. LM presenting in young adults tends to be smaller and with fewer dermoscopic features, making its diagnosis challenging. Careful evaluation of facial pigmented lesions prior to cosmetic procedures is imperative to avoid incorrectly treating early LM as a benign lesion.

Desmoplastic Melanoma Arising after 1,064 nm q-Switched Nd:YAG Laser of a Suspected Solar Lentigo

Objectives

To present a case of desmoplastic melanoma (DM) arising after laser therapy of a suspected solar lentigo with the 1,064 nm Q-switched (QS) Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser and discuss the safety of treating suspected solar lentigines with laser therapy.

Methods

Case presentation with discussion.

Results

We describe a patient who developed DM after 1,064 nm QS Nd:YAG laser therapy to a suspected solar lentigo.

Conclusions

Limited generalizable studies regarding the safety of laser therapy for solar lentigines exist, specifically for the 1,064 nm QS Nd:YAG laser. Therefore, we recommend caution is taken when considering laser therapy for these lesions, as well as strong consideration for histologic confirmation prior to therapy.

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.

Beneficial Effect of Low Fluence 1,064 nm Q-Switched Neodymium:Yttrium-Aluminum-Garnet Laser in the Treatment of Senile Lentigo

Background

Low fluence 1,064 nm Q-switched (QS) Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser treatment, also known as laser toning, is widely used for pigmentary disorders. There has been no reliable evaluation of the effect of low fluence 1,064 nm QS Nd:YAG laser for senile lentigo.

Objective

To investigate the beneficial effect of low fluence 1,064 nm QS Nd:YAG laser in the treatment of senile lentigo on the face.

Methods

A retrospective review was conducted on patients treated only with repetitive low fluence 1,064 nm QS Nd:YAG laser. Among them, 12 patients with multiple senile lentigines before treatment were included. All side effects were recorded to assess the safety of the modality.

Results

Mean age was 56.1±7.8 years old and male-to-female ratio was 1:11. Mean treatment fluence was 1.62±0.16 J/cm² and mean total treatment session was 8.8±2.6. Mean interval period between each session was 28.0±11.4 days and mean treatment session to reach marked and near total improvement was 8.7±2.8. At the final visit, seven of 12 (58.3%) patients reached marked and near total improvement, and three of 12 (25.0%) reached moderate improvement. No side effects occurred.

Conclusion

Repetitive low fluence 1,064 nm QS Nd:YAG laser treatment may be an effective and safe optional modality for senile lentigo.