FISH for Cutaneous Melanoma

Although the majority of melanomas can be distinguished from benign nevi on the basis of histologic criteria, a significant subset of melanocytic proliferations present conflicting features that preclude a definitive diagnosis for even the most expert pathologists. An unacceptably high number of lesions cannot be precisely and reproducibly classified as either entirely benign or malignant by routine histologic and immunohistochemical techniques. The morphologic limitations in the diagnosis of these histologically borderline lesions lead to both underand over-diagnosis of melanoma. Over-diagnosis of melanoma can lead to inappropriate therapy and psychologic burdens, whereas under-diagnosis can lead to inadequate treatment of a potentially deadly cancer.