Maximum malignant potential is seen in
The diagnosis can be made by visual inspection alone. Although most cases of blue nevi are benign, there is a small possibility that a cellular blue nevus can undergo malignant transformation and become a malignant cellular blue nevus (MCBN). Thus, a biopsy of any changing or suspicious lesion should be done Ref Harrison20th edition pg 1456
Epidermal nevus
Junctional nevus
Dermal nevus
Blue nevus
Skin tumors