[A new classification method of eyelid divided nevi and the effect of plastic surgical treatment].

To classify the eyelid divided nevi using a new classification method, and to observe the distribution characteristics and surgical effects of these nevi. It was a retrospective case series study. Thirty-nine cases (39 eyes) of eyelid divided nevus treated at Beijing Tongren Hospital affiliated to Capital Medical University were collected between October 2015 and January 2020. A new classification method, namely traditional classification combined with aesthetic unit classification, was used to classify eyelid divided nevi. According to different classifications, the corresponding surgical treatment methods were adopted. The distribution characteristics of different types of eyelid divided nevi were summarized, as well as the effects of plastic surgery. Thirty-nine patients were affected unilaterally, including 26 females (67%) and 13 males (33%), aged (31.1±17.8) years. There were 5 cases (13%) of localized, 6 cases (15%) of a moderate range and 2 cases (5%) of a large range medial eyelid divided nevus respectively. There were 6 cases (15%) of localized and 3 cases (8%) of a moderate range central eyelid divided nevus, respectively. There were 4 cases (10%) of localized and 6 cases (15%) of a moderate range lateral eyelid divided nevus, respectively. There were 2 cases (5%) of a moderate range and 5 cases (13%) of a large range total eyelid divided nevus, respectively. Pathological results revealed 20 cases of intradermal nevus (51%), 18 cases of compound nevus (46%) and 1 case of boundary nevus (3%). After 6 months to 2 years of observation, the patients' appearance was satisfactory. The treatment results were excellent in 36 cases (92%) and good in 3 cases (8%). Even though the pigmented nevus at the eyelid margin recurred in two cases (5%), there was no recurrence after reoperation. Medial and moderate-range eyelid divided nevi are more common, and the traditional classification combined with aesthetic unit classification is more accurate for the classification of eyelid divided nevi. Different types of eyelid divided nevi can be treated by corresponding surgical methods with satisfactory results.