Clinical and dermoscopic (in vivo and ex vivo) predictors of recurrent nevi.

Abstract

Recurrent nevi occur following removal of melanocytic nevi mainly after shaving excision. Due to its differential diagnosis with melanoma, its recognition can be challenging. To evaluate clinical and dermoscopic predictors of recurrent nevi. Clinical data on 224 melanocytic nevi were collected, together with dermoscopic images. Shave biopsy was performed and the underside of the surgical specimen was examined using ex vivo dermoscopy. A total of 195 lesions were followed for six months. Recurrent nevi were observed in 59 lesions. The occurrence of recurrent nevi was inversely associated with increased patient age. Darker skin phototypes and the compound nevus type were more associated with recurrence. Regarding dermoscopic features, the presence of dark brown colour, multiple colours, dots, terminal hair, and an annular-distributed pigmentation around adnexal structures were associated with recurrent nevi. Ex vivo dermoscopy showed that visible hyperpigmentation on the underside of the surgical specimen was correlated with recurrence. Multivariable analysis showed that annular hyperpigmentation and age were the most relevant predictors of recurrence. Individuals with dark skin type and young adults are at increased risk of recurrent nevi. Dermoscopy of the primary lesion and the underside of the surgical specimen are helpful in predicting recurrence after shave biopsy.