To investigate manifestations of connective tissue nevi (CTN) by dermoscopy and reflectance confocal miscroscopy (RCM) , and to analyze its pathological features.

According to the course of the disease, skin lesions of a patient with CTN were classified into 2 categories: skin lesions of less than 1-year duration and those of more than 1-year duration, which were observed by dermoscopy and RCM, and analyzed by the combination with histopathological examination.

Dermoscopy imaging of the CTN lesions of more than 1-year duration showed grey-white maculae with clear boundaries in the center of lesions. There were white network structures, brown globules, red spots and punctiform or comma-shaped blood vessels in the gray-white macula area, and vellus hairs and dermal papillary rings could be seen sometimes. The white macula was evenly surrounded by brown to black pigments, and the boundary was clear. For the lesions of less than 1-year duration, gray-white maculae with clear boundaries were also found in the center of the lesions. Besides, there were a few scattered brown to black pigments, vellus hairs and dermal papillary rings in the gray-white macula area. RCM imaging of the lesions of less than 1-year duration or early skin lesions showed dermal papillae of different sizes and shapes crowded with each other and formed a honeycomb or cobblestone-like structure. The density and brightness of the dermal papilla ring obviously increased, and the refraction of the dermal collagen fiber bundles was also enhanced. Some of the dermal collagen fiber bundles were attached to the dermal papilla or intertwined and arranged in a whirlpool pattern. For the lesions of more than 1-year duration, the refraction of the tissue structure was weakened when the depth in Z-axis direction reached 2 to 3 millimetres due to the thickened epidermis, while the dermal collagen fiber bundles were not obvious and only a few lymphocytes could be seen.

CTN has particular characteristics in dermoscopy, and there is a definite correspondence among dermoscopy features, histopathological findings and RCM features. RCM is helpful for the diagnosis of lesions of less than 1-year duration.

Dermoscopy; Microscopy, confocal; Pathologic process; Connective tissue nevi