Combined nevi (CN) are clinically defined as melanocytic lesions comprising two or more distinct melanocytic nevus components, and from the cytological point of view, CN are determined by the presence of two or more different nevus cell types in one biopsy specimen. They are very uncommon and represent less than 1% of all biopsied melanocytic nevi. CN comprise any melanocytic nevi, but the most prevalent combination is CN that consist of blue nevus associated with common melanocytic nevus. CN owe their diversity to combination of different nevi, that are variously combined. Consequently, they can have variable clinical aspects and dermatoscopic features. Because of the presence of at least two distinct subtypes of nevomelanocytes, dermatoscopically CN can show multicomponent, unspecific, and peculiar patterns. Therefore, CN can mimic melanomas, their most important differential clinical, dermatoscopical and histopathological diagnosis.
Part of the book: Dermatoscopy