Intralesional (incision) biopsy for melanoma diagnosis: the rules and the exception to the rules

Intralesional (incision) biopsy for melanoma diagnosis can be warranted for large lesions or for lesions whose in toto excision leads to cosmetic and/or functional impairment. However, this diagnostic approach carries a risk of underdiagnosis, if a clinicopathologic diagnostic approach is not implemented. As a rule, in large pigmented lesions from special body areas (scalp and acral skin), clinicodermoscopic differential diagnosis of melanoma includes non-melanocytic skin lesions, or traumatic skin changes, rather then nevi. The unique indication to incision biopsy for the differential diagnosis between nevus and melanoma is a relatively small nodular proliferation developing within a medium-large congenital nevus.