Nevo da epidermólise bolhosa: aspectos clínicos, dermatoscópicos e histológicos em um caso de portador da forma distrófica recessiva Epidermolysis bullosa nevi: clinical, dermatoscopical and histological features in a case of recessive dystrofic form

As lesões melanocíticas adquiridas podem apresentar aspecto clínico não-usual em pacientes portadores de epidermólise bolhosa hereditária. Essas lesões são conhecidas como "nevos EB" e, muitas vezes, constituem um desafio diagnóstico ao dermatologista por apresentarem características clínicas, dermatoscópicas e histopatológicas semelhantes às encontradas no melanoma. Não são exclusivas de nenhuma forma de epidermólise bolhosa e têm sua frequência aumentada na infância. Relata-se o caso de um doente do sexo masculino, de 6 meses de idade, portador da forma distrófica recessiva da doença, com lesão pigmentada de rápido crescimento na coxa esquerda. Optou-se por seguimento clínico da lesão, considerando que os aspectos clínicos, dermatoscópicos e histológicos eram compatíveis com a descrição de outros casos de nevo EB previamente descritos<br>Acquired melanocytic lesions may present unusual clinical features in all forms of hereditary epidermolysis bullosa. These lesions are known as "EB nevi", and often pose a diagnostic challenge for dermatologists given their resemblance - clinically, dermoscopically and histologically - to melanoma. The lesions have been reported in all types of hereditary EB, most of them in childhood. We report the case of a 6-month-old boy suffering from recessive dystrophic epidermolysis bullosa (RDEB) that presented as a large pigmented lesion on his left thigh. We decided to monitor the lesion closely since we considered that the clinical and pathological aspects of the lesion were compatible with the description of other previously reported cases of EB nev

Nevo da epidermólise bolhosa: caso clínico e revisão da literatura Epidermolysis bullosa nevus: case report and literature review

Lesões melanocíticas adquiridas assemelhando-se à melanoma têm sido descritas nos principais grupos da Epidermólise bolhosa, e referidas como "Nevos da Epidermólise bolhosa''. Induzem facilmente ao erro diagnóstico, apesar de nenhuma transformação maligna ter sido descrita. Relatamos o desenvolvimento de um nevo melanocítico adquirido grande no local de bolhas recorrentes em uma criança de 5 anos portadora de Epidermólise bolhosa simples. O padrão dermatoscópico global foi sugestivo de benignidade, e os achados histopatológicos foram compatíveis com um nevo melanocítico composto. Este é o primeiro caso de um Nevo da Epidermólise bolhosa publicado na literatura brasileira<br>Acquired melanocytic lesions resembling malignant melanoma have been described in all major categories of Epidermolysis bullosa and referred to as "Epidermolysis bullosa nevi''. They easily induce to diagnostic error, although no malignant transformation has been reported. We report the development of a large acquired melanocytic nevus at a site of recurrent blisters in a 5-year-old child with Epidermolysis bullosa simplex. The global dermoscopic pattern was suggestive of benignity, and the histopathological findings were compatible with a compound melanocytic nevus. This is the first published case of Epidermolysis bullosa nevi in Brazilian literature. Despite their benign behavior, we emphasize the importance of regular clinical and dermoscopic monitoring, since a malignant course still cannot be totally exclude

Collagen XVII is expressed in malignant but not in benign melanocytic tumors and it can mediate antibody induced melanoma apoptosis

The 180 kDa transmembrane collagen XVII is known to anchor undifferentiated keratinocytes to the basement membrane in hemidesmosomes while constitutively shedding a 120 kDa ectodomain. Inherited mutations or auto-antibodies targeting collagen XVII cause blistering skin disease. Collagen XVII is down-regulated in mature keratinocytes but re-expressed in skin cancer. By recently detecting collagen XVII in melanocyte hyperplasia, here we tested its expression in benign and malignant melanocytic tumors using endodomain and ectodomain selective antibodies. We found the full-length collagen XVII protein in proliferating tissue melanocytes, basal keratinocytes and squamous cell carcinoma whereas resting melanocytes were negative. Furthermore, the cell-residual 60 kDa endodomain was exclusively detected in 62/79 primary and 15/18 metastatic melanomas, 8/9 melanoma cell lines, HT199 metastatic melanoma xenografts and atypical nests in 8/63 dysplastic nevi. The rest of 19 nevi including common, blue and Spitz subtypes were also negative. In line with the defective ectodomain, sequencing of COL17A1 gene revealed aberrations in the ectodomain coding region including point mutations. Collagen XVII immunoreaction-stained spindle cell melanomas, showed partly overlapping profiles with those of S100B, Melan A and HMB45. It was concentrated at vertical melanoma fronts and statistically associated with invasive phenotype. Antibody targeting the extracellular aa507-529 terminus of collagen XVII endodomain promoted apoptosis and cell adhesion, while inhibiting proliferation in HT199 cells. These results suggest that the accumulation of collagen XVII endodomain in melanocytic tumors is associated with malignant transformation to be a potential marker of malignancy and a target for antibody-induced melanoma apoptosis. © 2012 Springer-Verlag