Benign Nevi

Benign melanocytic nevi are histologically well circumscribed lesions with nests of cells confined to the DEJ in junctional nevi, DEJ and papillary dermis in compound nevi and purely in the dermis in dermal nevi. 
Nevus cells can be described as Type A when they have epitheliod features with prominent cytoplasm. Type B when they are more like packed lymphocytes with a lesser cytoplasm and prominant nucleus and Type C when they are spindled cells in the deeper dermis. They show very few mitoses and the nevus cells disperse at the base rather than forming an expanding wall of cells as is seen in melanoma.

Look at the Presentation below and then View the Visual Slides.

Compound Nevus      Intradermal Nevus

Congenital nevus

Blue Nevus       Cellular Blue nevus    Epitheliod Blue Nevus    

Also view this video on The histopathology of Benign nevi by a Dermatopathologist.