Dermatology: Practical and Conceptual Letter | Dermatol Pract Concept 2019;9(2):19 165 Dermatology Practical & Conceptual Introduction Recurrent melanocytic nevus (RMN) is the name given to melanocytic lesions that grow after previous partial excision, usually by shaving. It presents a proliferation of melano- cytes whose clinical aspect may be difficult to differenti- ate from melanoma, being therefore denominated pseu- domelanoma [1]. Case Presentation A 6-year-old girl was referred for evaluation of a melanocytic lesion in the right lower limb, noted 5 months after a third- degree burn in the same area and with progressive growth, according to a family member. Clinical examination revealed a hyperchromic macula, with 2 cm in the largest diameter and presence of light and dark brown areas and irregular borders (Figure 1). The dermoscopic features found were light brown and dark brown blotches, border asymmetry, and streaks at the periphery of the lesion (Figure 2). Confocal microscopy revealed single bright, nucleated cells of varying sizes and shapes in the suprabasal epidermis (Figure 3). After 3 months, lesion growth was verified by means of comparative analysis of dermoscopy images (Figure 4). We opted for excision of the lesion and the specimen was sent for histopathological analy- sis, which revealed hyperkeratosis traversed by well-defined melanin pigment columns, atypical melanocytic proliferation in the lower layers of the epidermis, and a cicatricial fibrosing inflammatory process occupying the reticular dermis. The histological picture was consistent with junctional RMN associated with extensive scarring (Figure 5). No pagetoid migration of melanocytes or mitotic figures was observed. Discussion Many theories have been proposed to clarify the possible ori- gin of RMN. Among them, the proliferation of melanocytes in the adjacent epidermis, the proliferation of melanocytes from remnant adnexal structures, or the growth from residual intradermal melanocytic nevi are highlighted. It is known that 50% of recurrences are noted within 6 months of the surgical procedure. In a series of 80 cases studied by King et al., the Recurrent Nevus After Burn Injury Raquel Nardelli de Araujo1, Marcelle Klein de Araújo2, Juan Piñeiro-Maceira1,3, Carlos Baptista Barcaui1,3 1 Department of Dermatology, Pedro Ernesto University Hospital, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil 2 Ipanema Federal Hospital, Rio de Janeiro, Brazil 3 Dermatology, Faculty of Medical Sciences, State University of Rio de Janeiro, Brazil Key words: recurrent nevus, burn injury Citation: Nardelli de Araujo R, Klein de Araújo M, Piñeiro-Maceira J, Baptista Barcaui C. Recurrent nevus after burn injury. Dermatol Pract Concept. 2019;9(2):165-167. DOI: https://doi.org/10.5826/dpc.0902a19 Accepted: February 5, 2019; Published: April 30, 2019 Copyright: ©2019 Nardelli de Araujo 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. Authorship: All authors have contributed significantly to this publication. Corresponding author: Raquel Nardelli de Araujo, MD, Department of Dermatology, Pedro Ernesto University Hospital, University of the State of Rio de Janeiro, Boulevard 28 de setembro, 77. Vila Isabel, Rio de Janeiro - RJ, Brazil, 20551-030. Email: raquelnardelli@yahoo. com.br 166 Letter | Dermatol Pract Concept 2019;9(2):19 lesions seemed to be completely excised, which would suggest that the regrowth from residual nevus was unlikely [1]. In our case, no previous lesion in the right lower limb was referred before the burn injury. Melanocytic lesions in large burns configure a challenge for dermatolo- gists due to clinical and dermoscopic aspects. They can be classified clinically and histologically in reactive cicatricial pigmentation, recurrent nevus, incom- pletely excised melanoma, or metastatic melanoma [1,2]. No RMN descriptions were found in large burns. However, the authors emphasize that RMN should be remembered as a possibility due to tis- sue injury and scarring caused by burns. C o n s i d e r i n g t h a t m o r p h o l o g i- cal changes of pigmented lesions are described as significant predictors of malignancy, it has been suggested that RMN would be an exception to this rule, since the continuous clinical modi- fications may occur over time as evi- denced in the case described. However, it does not increase the risk for mela- noma development. As a general rule, in these cases the pigment will not extend beyond the scar and the majority remain stable for years [2]. Figure 1. Pigmented macula, with 2 cm in the largest diameter and with light and dark brown areas and irregular borders. [Copy- right: ©2019 Nardelli de Araujo et al.] Figure 2. Dermoscopy shows light brown and dark brown blotches, border asymme- try, and streaks in the periphery of the le- sion. [Copyright: ©2019 Nardelli de Araujo et al.] Figure 3. Confocal microscopy shows single bright, nucleated cells of varying sizes and shapes in the suprabasal epidermis. [Copyright: ©2019 Nardelli de Araujo et al.] Figure 4. Dermoscopy performed 3 months after the first dermoscopy evaluation shows progressive enlargement beyond the burn scar with an increase in the irregular streaks. [Copyright: ©2019 Nardelli de Araujo et al.] Figure 5. Histopatho- logical analysis. Atypi- cal melanocytic prolifer- ation in the lower layers of the epidermis and the intradermal compo- nent with a cicatricial inflammatory process (hematoxylin and eo- sin, ×200). [Copyright: ©2019 Nardelli de Araujo et al.] Letter | Dermatol Pract Concept 2019;9(2):19 167 References 1. King R, Hayzen BA, Page RN, Googe PB, Zeagler D, Mihm MC Jr. Recurrent nevus phenomenon: a clinicopathologic study of 357 cases and histologic comparison with melanoma with regression. Mod Pathol. 2009;22(5):611-617. 2. Longo C, Moscarella E, Pepe P, et al. Confocal microscopy of recur- rent naevi and recurrent melanomas: a retrospective morphological study. Br J Dermatol. 2011;165(1):61-68. Conclusions We emphasize the importance of clinical, dermoscopic, and histopathological evaluation of melanocytic lesions in large burns by dermatologists to avoid possible diagnostic errors and unnecessary interventions.