Malignant melanoma arising in the setting of epidermolysis bullosa simplex: an important distinction from epidermolysis bullosa nevus.

[epidermolysis bullosa simplex]

Patients with epidermolysis bullosa (EB ) do not carry a significantly increased risk of melanoma but are prone to developing large , markedly atypical melanocytic nevi (EB nevi ), which may mimic melanoma clinically and histologically . Many authors now favor a conservative approach in managing atypical pigmented lesions in patients with EB .We present the case of a 30 -year -old woman with severe EB simplex who sought care for a large red and black ulcerated plaque . The clinical differential diagnosis included EB nevus and melanoma . An incisional punch biopsy specimen revealed an atypical melanocytic proliferation with focal florid pagetoid spread and involving elongated rete ridges , consistent with invasive acral lentiginous melanoma . The subsequent amputation was confirmatory . Micrometastasis was detected in 1 of 5 sentinel lymph nodes .To our knowledge , this is the first reported case of melanoma arising in EB simplex-affected skin . It highlights the difficulty in differentiating melanoma from an EB nevus . Despite the increasing awareness of EB nevi , a high index of suspicion for melanoma should be maintained , and early biopsy is recommended when evaluating large pigmented lesions in patients with EB .