Eruptive large melanocytic nevus in a patient with hereditary epidermolysis bullosa simplex.

Hereditary epidermolysis bullosa (HEB) is a group of genetically determined mechanobullous disorders characterized by blister formation following minor trauma. Unusual melanocytic lesions may be a rare feature of all major categories of HEB. We report a large melanocytic nevus, clinically simulating malignant melanoma, which developed at a site of healing blisters in an 8-year-old male with recessive generalized epidermolysis bullosa simplex (EBS). Histological findings were consistent with a compound nevus. This is the third reported case of an eruptive melanocytic nevus developing in EBS. Due to their unique features, it has been suggested that these nevi may represent a distinct variant, referred to as epidermolysis bullosa nevi. Despite the atypical picture, no malignant transformation of HEB nevi has been seen. Therefore, after histologic verification, regular long-term follow-up rather than radical surgery is recommended.