Untitled Case Report | Dermatol Pract Concept 2015;5(2):20 99 DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Introduction The use of lasers and intense pulsed light (IPL) technology has become an established practice in dermatology and aesthetic medicine. The number of treatments performed with lasers and IPL has increased remarkably in the last two decades. An 810 nm, high-power diode laser system (LightSheer™ Diode Laser [Lumenis Ltd, Yokneam, Israel]) is among one of the newer lasers now available for hair removal [1,2]. We report clinical, dermoscopic and histological features of a complete regressed pigmented melanocytic nevus after hair removal treatment with LightSheer Diode Laser. Case report A 30-year-old woman with multiple acquired melanocytic nevi and Fitzpatrick skin type III, presented for digital dermoscopy. She had a family history of malignant melanoma (in her father) and reported recent changes in a pigmented mole of unknown duration in her right calf. Upon examination, this pigmented lesion measured 5 mm in diameter, was dark brown in color (Figure 1) and displayed a homogeneous disorganized Complete regression of a melanocytic nevus after epilation with diode laser therapy Manuela Boleira1, Laila Klotz de Almeida Balassiano1, Thiago Jeunon3 1 Dermatology, Policlínical Geral do Rio de Janeiro (PGRJ), Brazil 2 Dermatopathology, Hospital Federal de Bonsucesso (HFB); ID—Investigação em Dermatologia, Rio de Janeiro, Brazil Key words: laser, regression, melanocytic nevus, dermatoscopy, histopathology Citation: Boleira M, Balassiano LK, Jeunon T. Complete regression of a melanocytic nevus after epilation with diode laser therapy Dermatol Pract Concept 2015;5(2):20. doi: 10.5826/dpc.0502a20 Received: December 15, 2014; Accepted: January 26, 2015; Published: April 30, 2015 Copyright: ©2015 Boleira et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: None. Competing interests: The authors have no conflicts of interest to disclose. All authors have contributed significantly to this publication. Corresponding author: Manuela Boleira, Av. Nilo Peçanha, 38. Centro, 20020-100. Rio de Janeiro—RJ. Brazil. Tel: +55 21 98187-9939; Fax: +55 21 3619-1511. Email: manubsg@yahoo.com.br The use of lasers and intense pulsed light (IPL) technology has become an established practice in der- matology and aesthetic medicine. The use of laser therapy and IPL in the treatment of pigmented me- lanocytic lesions is a controversial issue. We report clinical, dermoscopic and histological changes of a completely regressed pigmented melanocytic nevus after hair removal treatment with the LightSheer™ Diode Laser (Lumenis Ltd, Yokneam, Israel). ABSTRACT Figure 1. Melanocytic lesion in the right calf, measured 5 mm and dark-brownish in color. [Copyright: ©2015 Boleira et al.] 100 Case Report | Dermatol Pract Concept 2015;5(2):20 presumably a melanocytic nevus, secondary to previous laser therapy was rendered (Figure 4). The histopathologic diagno- sis prompted an active inquiry for previous laser therapies, and it was discovered that the patient had undergone cosmetic removal of leg hair with an 810 nm, pulsed, high-power diode laser (LightSheer Diode Laser) 15 days prior to the biopsy. Discussion The majority of lasers used for hair removal target melanin as the chromophore, consequently there are limitations and potential side effects mostly pertaining to alterations in pigmentation. In healthy skin, the higher density of melanin within the hair shaft and within the follicular matrix cells as well the presence the larger and more heavily melanized mela- nosomes relative to the epidermis contributes to the preferen- tial targeting of melanin in the hair follicle over melanin in the epidermis. In a nevus, the increased number of melanocytes and melanin suggests that the photons of the laser for hair removal might be absorbed by the neoplastic melanocytes and pigmented keratinocytes, resulting in aforementioned clinical, dermoscopic and histological changes. In patients with multiple Clark’s nevi or with a personal or family history of melanoma, a mole undergoing changes in clinical or dermoscopic features during a period of follow- up or with a distinct morphology in comparison to the other nevi are concerning findings [3]. These changes or atypical findings often warrant that a biopsy be performed to rule out malignancy [3-6]. pattern on dermoscopy (Figure 2), differing from the other nevi located on the abdomen and back region which exhib- ited a predominantly reticular pattern (Figure 3). There were no clinical signs of inflammation. This lesion was considered suspicious and an excisional biopsy was performed to rule out melanoma. Histologically, there was scale-crust permeated by melanin situated above a basket-weave stratum corneum and, at the center of the lesion, there was a geometric triangu- lar area of basophilic collagen degeneration with the vertex pointed downwards in the papillary dermis characteristic of laser injury and numerous associated melanophages. There was no evidence of a residual melanocytic neoplasm in the sections of tissue examined. Imunohistochemical stains using anti-S100 protein, anti-Melan-A and anti-HMB45 primary antibodies were unable to show scattered residual neoplastic melanocytes. The diagnosis of a regressed pigmented lesion, Figure 2. Homogeneous disorganized pattern on dermoscopy. [Copyright: ©2015 Boleira et al.] Figure 3. Digital dermoscopy of others nevi located on the abdomen and back region showed a diffuse regular reticular pattern with a deli- cate pigment network, ranging from light to dark brown in color. [Copyright: ©2015 Boleira et al.] Case Report | Dermatol Pract Concept 2015;5(2):20 101 dermoepidermal junction and in pagetoid distribution within the epidermis, simulating malignant melanomas. However, the distinction is possible because in the former these findings are restricted to the area above the dermal fibrosis, while in the latter they often extend beyond it [13-16]. In cases where an unequivocal distinction between recurrent nevus and melanoma cannot be achieved, review of the previous biopsy (when available) usually resolves the quandary. There are also cases in which a diagnosis of melanoma has been made subsequent to laser treatment of a melanocytic lesion. We believe some of these lesions were actually mela- nomas from the outset and, therefore, inadequately treated with lasers, while others could have been nevi that displayed changes of recurrent nevus (pseudomelanoma) after laser therapy that were ultimately misconstrued as transformation of a nevus in melanoma [1,5]. An electronic search on the PubMed database yielded a small number of publications regarding changes in mela- nocytic nevi after hair removal treatment with laser or IPL. This is summarized in Table 1, which includes two cases that The patient herein presented experienced complete histo- logical involution presumably of a melanocytic nevus after diode laser therapy. Since the lesion was biopsied just 15 days after epilation, it was possible to identify the characteristic geometrical collagen degeneration that prompted the recogni- tion of laser damage, as well the presence of crust permeated by melanin atop the corneum layer [7,8,9]. If the lesion were biopsied substantially later, it would have displayed super- ficial dermal fibrosis in conjunction with melanophages, similar to previous case reports of completely regressed melanocytic nevi after laser therapy [1,10,11,12]. In some instances, melanocytic nevi have persisted after laser injury. In such cases, the residual neoplasm displayed dermoscopic and histopathological changes similar to those seen in recurrent nevi (so called pseudomelanomas) occur- ring in surgical scars. With dermoscopy, these lesions may exhibit irregular network, streaks, globules of variable sizes and colors and dark brown blotches over a white scar area. Histopathologically, recurrent/persistent nevi may present variably atypical melanocytes irregularly disposed along the A B C D Figure 4. (A) Scale-crust and melanin granules over a reticular stratum corneum. Papillary dermis showed basophilic degeneration of colla- gen. H&E, x10. (B) Papillary dermis showed basophilic degeneration of collagen in a triangular shape with the apex pointing downward and melanophages. H&E, x40. (C) Basophilic degeneration of collagen in a triangular shape with the apex pointing downward and peripheral melanophages. H&E, x100. (D) A close-up to the scale-crust permeated by melanin. H&E, 100x. [Copyright: ©2015 Boleira et al.] 102 Case Report | Dermatol Pract Concept 2015;5(2):20 therapy for axillary hair removal in a cosmetic center. Dermatol- ogy 2012;224(3):193-7. 2. Souza FHM, Ribeiro CF, Weigert S, et al. The use of 810 nm diode laser versus intense pulsed light (filter 695 nm) in axil- lary epilation: a comparative study. Surg Cosmet Dermatol 2010;2(3):185-90. 3. Fikrle T, Pizinger K, Szakos H, et al. Digital dermatoscopic follow- up of 1027 melanocytic lesions in 121 patients at risk of malig- nant melanoma. J Eur Acad Dermatol Venereol 2013;27(2):180-6. 4. Soden CE, Smith K, Skelton H. Histologic features seen in chang- ing nevi after therapy with an 810 nm pulsed diode laser for hair removal in patients with dysplastic nevi. Int J Dermatol 2001;40(8):500-45. 5. Sillard L, Mantoux F, Larrouy JC, Hofman V, Passeron T, Lacour JP, Bahadoran P. Dermoscopic changes of melanocytic nevi after laser hair removal. Eur J Dermatol 2013; 23(1):121-3. 6. Garridos-Ríos A, Muñoz-Repeto I, Huerta-Brogeras M, et al. Dermoscopic changes in melanocytic nevi after depilation tech- niques. J Cosmet Laser Ther 2013; 15(2):98-101. 7. Drnovsek-Olup B, Beltram M, Pizem J. Repetitive Er:YAG laser irradiation of human skin: a histological evaluation. Lasers Surg Med 2004; 35(2):146-51. 8. Hardaway CA, Ross EV, Barnette DJ, Paithankar DY. Non- ablative cutaneous remodeling with a 1.45 microm mid-infrared diode laser: phase I. J Cosmet Laser Ther 2002;4(1):3-8. 9. Reda AM, Taha IR, Riad HA. Clinical and histological effect of a single treatment of normal mode alexandrite (755 nm) la- ser on small melanocytic nevi. J Cutan Laser Ther 1999;1(4): 209-15. 10. Westerhof W, Gamei M. Treatment of acquired junctional me- lanocytic nevi by Q-switched and normal mode ruby laser. Br J Dermatol 2003; 148(1):80-5. 11. Baba M, Bal N. Efficacy and safety of the short-pulse erbium:YAG laser in the treatment of acquired melanocytic nevi. Dermatol Surg 2006; 32(2):256-60. 12. Piccolo D. The Usefulness of Dermoscopy in Laser and Intense Pulsed Light Treatments. Florence: Remo Sandron Editor, 2012. 13. Trau H, Orenstein A, Schewach-Millet M, Tsur H. Pseudomela- showed complete histological regression of a melanocytic nevus under intense pulsed light therapy for axillary hair removal [1,4,5,6,12]. Conclusion Hair removal with lasers in areas containing melanocytic nevi may result in incidental treatment of nevi and subsequent changes in clinical and dermoscopic features, which, in turn, may raise suspicion for melanoma, especially in patients with multiple risk factors. Dermatologists should be aware of this phenomenon and be careful to avoid melanocytic nevi while treating an anatomic area with laser for epilation. Despite many publications reporting treatment of melanocytic nevi with lasers, it remains a controversial issue. In our opinion, laser therapy should not be considered a routine indication for melanocytic lesions that have not been biopsied and histopathologically evaluated and in the event of incomplete treatment may induce changes that could simulate malignant melanoma. When presented with a melanocytic nevus that has undergone recent change in an area previously treated with laser epilation, dermatologists should be mindful that it might represent a “recurrent nevus” rather than a melanoma. Moreover, it is essential that the pathologist interpreting the biopsy be provided with as much clinical information as possible, minimizing the possibility of erroneously rendering a diagnosis of melanoma and consequently unnecessary surgi- cal procedures, adjuvant treatment and follow-up regimens. References 1. Martín J, Monteagudo C, Bella R, Reig I, Jordá E. Complete regression of a melanocytic nevus under intense pulsed light TABLE 1. Reports of melanocytic nevi that changed after hair removal treatment with laser or intense pulsed light. First author Clinical evaluation Laser type Outcome Soden, 2001 [3] Four melanocytic nevi Diode laser Clinical changes Martin, 2012 [1] One melanocytic nevus Intense pulsed light Complete regression, histologically confi rmed Sillard, 2013 [4] Two melanocytic nevi Intense pulsed light Dermoscopic changes Garrido-Ríos, 2013 [5] Patient 1—Two melanocytic nevi Patient 2—Two melanocytic nevi Patient 3—several melanocytic nevi (no specifi c number) Diode laser Alexandrite laser Intense pulsed light Dermoscopic and histopathological changes Dermoscopic and histopathological changes Clinical and dermoscopic changes Piccolo 2012 [11] Patient 1—melanocytic nevus Patient 2—congenital nevus Intense Pulsed Light Complete regression, histologically confi rmed Dermoscopic changes; No signifi cant changes histologically Case Report | Dermatol Pract Concept 2015;5(2):20 103 15. Hwang K, Lee WJ, Lee SI. Pseudomelanoma after laser therapy. Ann Plast Surg 2002; 48(5):562–4. 16. Lee HW, Ahn SJ, Lee MW, et al. Pseudomelanoma following laser therapy. J Eur Acad Dermatol Venereol 2006;20(3):342–3. noma following laser therapy for congenital nevus. J Dermatol Surg Oncol 1986;12(9):984–6. 14. Dummer R, Kempf W, Burg G. Pseudo-melanoma after laser therapy. Dermatology 1998;197(1):71–3.