Dermoscopy of cutaneous neurofibromas associated with neurofibromatosis type 1
2015; Elsevier BV; Volume: 73; Issue: 3 Linguagem: Inglês
10.1016/j.jaad.2015.05.021
ISSN1097-6787
Autores Tópico(s)Soft tissue tumors and treatment
ResumoTo the Editor: Neurofibroma is a tumor of nerve sheath origin that is characterized by a solitary soft to firm papule/nodule and the buttonhole sign.1Argenyi Z.B. Neural and neuroendocrine neoplasms.in: Bologna J.L. Jorizzo J.L. Schaffer J.V. Dermatology. 3rd ed. Mosby Elsevier, London2012: 1949-1950Google Scholar Diagnosing the multiple form of neurofibroma based on clinical findings is usually not difficult; however, accurate diagnosis of the solitary form or pigmented lesions can be difficult. The dermoscopic features of neurofibromas are not well characterized. We aimed to describe the dermoscopic features of neurofibromas in a series of 5 patients with neurofibromatosis type 1 (NF1). The study included 26 lesions in 5 patients with NF1. The inclusion criteria were as follows: (1) ≥1 histopathologically proven neurofibroma in each patient and (2) clinically typical cutaneous neurofibromas with the buttonhole sign. Sex, age, lesion localation, clinical pigmentation, and association between the lesions and pigmentary skin lesions (ie, underlying café au lait macule [CALM] or freckles extending beyond the borders of the lesion) were recorded. Dermoscopic images and photographs were obtained at ×10 magnification using a Heine Delta 20 plus nonpolarized dermoscope and a Heine single-lens reflex photoadaptor (Heine Optotechnik, Herrsching, Germany) and a Canon EOS 600 D digital single-lens reflex camera (Canon USA, Melville, NY). The study protocol was approved by the institutional ethics review board. Definitions of the dermoscopic features observed in the study are listed in Table I.Table IDefinition of dermoscopic features observed in neurofibroma lesionsDermoscopic featureDefinitionPeripheral pigment networkRegular or irregular brown network extending the borders of the lesionPeripheral halo of brown pigmentationContinuous or discontinuous dark or light brown homogeneous pigmentation at the bordersFingerprint-like structuresBrown, fine, parallel cord-like structuresBlood vesselsAny type of vessels observed throughout the lesionPink-red structureless areasPink to red areasFissuresIrregular linear cryptsScar-like areasOpaque white distinct areas Open table in a new tab The mean patient age was 25.4 ± 11.9 years, and the female:male ratio was 2:3. All 26 lesions were located on the trunk, of which 21 (81%) were associated with CALM/freckles and clinically pigmented lesions (Fig 1). Dermoscopic evaluation of all the lesions revealed 7 major dermoscopic features, including a peripheral pigmented network (n = 21), a peripheral halo of brown pigmentation (n = 19), pink-red structureless areas (n = 12), fingerprint-like structures (n = 11), scar-like areas (n = 9), fissures (n = 9), and blood vessels (n = 6; Fig 2). A peripheral pigment network (100% vs 0%; P < .001), a halo of brown pigmentation (81% vs 40%; P = .064), and fingerprint-like structures (52% vs 0%; P = .033) were observed more frequently in pigmented lesions associated with CALM/freckles; however, pink-red structureless areas (100% vs 33%; P = .012), blood vessels (80% vs 9.5%; P = .006), and scar-like areas (80% vs 24%; P = .034) were significantly more common in lesions that were not associated with CALM/freckles. Fissures were observed with similar frequency in both groups (38% vs 20%; P = .445).Fig 2Dermoscopic features observed in neurofibromas: a peripheral pigment network (A and D, black arrows); a peripheral halo of brown homogeneous pigmentation (B and C, white arrows); fingerprint-like structures (D and F, black arrowheads); pink-red structureless areas (E and G, white asterisks); fissures (B, white arrowheads); and scar-like areas (E and H, black asterisks).View Large Image Figure ViewerDownload Hi-res image Download (PPT) The primary differential diagnosis of neurofibroma includes dermal melanocytic nevus and acrochordon.1Argenyi Z.B. Neural and neuroendocrine neoplasms.in: Bologna J.L. Jorizzo J.L. Schaffer J.V. Dermatology. 3rd ed. Mosby Elsevier, London2012: 1949-1950Google Scholar The most common dermoscopic features of dermal nevi include a papillomatous/smooth surface, comma-like vessels, residual brown-gray globules, a few milia-like cysts or comedo-like openings, and hairs.2Zalaudek I. Kreusch J. Giacomel J. et al.How to diagnose nonpigmented skin tumors: a review of vascular structures seen with dermoscopy: part I. Melanocytic skin tumors.J Am Acad Dermatol. 2010; 63: 361-374Abstract Full Text Full Text PDF PubMed Scopus (199) Google Scholar To the best of our knowledge, specific dermoscopic features for acrochordons have not been reported. In conclusion, the present findings indicate that the dermoscopic features of neurofibromas associated with underlying CALM/freckles usually have pigmentary structures; however, nonpigmented neurofibromas not associated with underlying CALM/freckles in most cases feature scar-like areas, pink-red structureless areas, and blood vessels. The dermoscopic features described in the present study can be used as supplementary criteria for diagnosing neurofibromas when the diagnosis is uncertain.
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