RESUMO
Background: Dermoscopy is useful in the diagnosis of basal cell carcinoma (BCC). However, most descriptions of the dermoscopic features of BCCs are in Caucasians (skin types I-III) and there is a paucity of data in dark-skinned Indian patients. Aims: The aim of this study was to describe the various dermoscopic features of BCC in dark-skinned patients from South India and correlate these with the histopathologic subtypes. Methods: A retrospective observational study of biopsy-proven cases of BCC was conducted at a tertiary care center in South India using nonpolarized contact dermoscopy. Results: Sixty BCCs in 35 patients predominantly of skin phototypes IV or V were studied. These included 32 nodular, 27 superficial and 1 infiltrative type of BCC. The most common dermoscopic features noted were maple leaf-like areas (61.7%), blue-white veils (53.4%), ulceration (48.4%) and short fine telangiectases (46.7%). Ulceration, blue-white veils and arborizing vessels were significantly associated with nodular BCCs, while maple leaf-like areas, red-white structureless areas, multiple small erosions and spoke wheel areas were noted with superficial BCCs. Limitations: The limitations of this study include its retrospective nature, the use of only nonpolarized light for examination, the lack of other histopathological variants of BCC as well as the lack of a comparison group. Conclusion: We report a dermoscopic study of BCC in dark-skinned patients from Puducherry, South India. The blue-white veil was observed in half of the patients and was significantly associated with nodular BCCs. The addition of the blue-white veil to the diagnostic criteria for pigmented BCC could improve the diagnostic accuracy of dermoscopy in Indian patients.
RESUMO
Los nevi azules son proliferaciones melanocíticas dendríticas benignas a nivel dérmico, congénitos o adquiridos, debido a un defecto migratorio embrionario de melanocitos a partir de la cresta neural. Se manifiestan clásicamente como una pápula, nódulo o placa de color azul o azul-gris. Muchos subtipos histológicos se han descrito, siendo los más comunes el nevus azul común, nevus azul celular y nevus azul combinado. Las formas esporádicas incluyen al nevus azul lineal, eruptivo, agminado y con satelitosis. La dermatoscopía característica muestra un patrón de pigmentación homogéneo monocromático azul o azul-grisáceo, con ausencia de otras estructuras. Sin embargo, se han descrito también patrones de pigmentación dicromáticos y multicromáticos, además de estructuras tales como red de pigmento, puntos, glóbulos, proyecciones radiadas, pseudópodos, áreas cicatriciales blanquecinas, patrón vascular y rosetas. El diagnóstico diferencial de los nevi azules incluye lesiones melanocíticas y no melanocíticas, benignas y malignas, destacando entre ellas el melanoma. Se presenta el caso de un paciente de sexo masculino de 30 años, portador de un nevus azul celular con cambios de rápida evolución, con desarrollo de lesiones satélites y un aspecto dermatoscópico sugerente de malignidad, simulando un melanoma.
Blue nevi are benign, congenital, or acquired, dermal dendritic melanocytic proliferations due to an embryonic migratory defect of melanocytes starting from the neural crest. They classically manifest as a blue or blue-gray papule, nodule, or plaque. Many histological subtypes have been described, including common blue nevus, cellular blue nevus and combined blue nevus. Sporadic forms include linear blue nevus, eruptive, agminate and with satellitosis. Characteristic dermoscopy shows a homogeneous monochromatic blue or steel-blue pigmentation pattern, with the absence of other structures. However, dichromatic and multichromatic pigmentation patterns have also been described, in addition to structures such as pigment network, dots, globules, streaks, pseudopods, whitish scar areas, vascular pattern and rosettes. Differential diagnosis of blue nevi includes melanocytic and non-melanocytic, benign and malignant lesions, most notably melanoma. The case of a 30-year-old male patient is presented, with a cellular blue nevus with rapidly evolving changes, with development of satellite lesions and a dermoscopic appearance suggestive of malignancy, mimicking melanoma.