Nevi

Nevi are benign proliferation of various cell types in the skin that can be present at birth (congenital nevi) or develop later in life (acquired nevi). Melanocytic nevi are the most common type of nevi composed of melanocytes. Large congenital melanocytic nevus is associated with a higher risk of developing melanoma. Epidermal nevi originate from the epidermis and/or adnexal structures of the skin. Common epidermal nevi include keratinocytic epidermal nevus and nevus sebaceus. Connective tissue nevi result from excessive proliferation of various components of the dermis and may appear as sporadic lesions or associated with syndromes. Vascular nevi are congenital capillary malformations, resulting in various clinical presentations. A port-wine stain or nevus flammeus is the most common type of capillary malformation.