To investigate dermoscopic and reflectance confocal microscopic (RCM) features of sebaceous nevus in patients of different ages.

A total of 83 patients histopathologically diagnosed with sebaceous nevus were enrolled from Department of Dermatology of Wuhan No. 1 Hospital between January 2016 and December 2016, and divided into 4 age groups (< 10 years, 10 - 20 years, 21 - 59 years, ≥ 60 years) according to the age. The dermoscopic and RCM features were collected and analyzed.

Among the age group of < 10 years (21 cases) , dermoscopic images of skin lesions showed that uniform, globular or plaque-shaped yellowish-red structures arranged in a cobblestone-like pattern were independently distributed in an orange background, with vascular proliferation and dilatation, while RCM images showed sebaceous gland hypoplasia and juvenile hair follicles. Among the age group of 10 - 20 years (28 cases) , dermoscopy showed aggregated, non-hair follicle, round or oval yellow structures of varying sizes with telangiectases, while RCM showed botryoidal sebaceous glands at the dermal-epidermal junction and superficial dermis, which were characterized by tube-like or handle-like structure in the center, aggregated fish roe-like or frogspawn-like sebaceous gland lobules in the surrounding area and verrucous or papillomatous hyperplasia in the epidermis. The age groups of 21 - 59 years (30 cases) and 10 - 20 years showed the similar imaging manifestations. The main imaging manifestation of the age group of ≥ 60 years (4 cases) was papillomatous hyperplasia.

Sebaceous nevus is a dynamic developmental disease, and its imaging characteristics obviously differ among different age stages. Sebaceous nevus has characteristic structures under dermoscopy and RCM, which can serve as efficient noninvasive diagnostic methods for sebaceous nevus.

Sebaceous gland neoplasms; Microscopy, confocal; Dermoscopy; Sebaceous nevus