The potential diagnostic and predictive role of anaplastic lymphoma kinase (ALK) gene alterations in melanocytic tumors.

Anaplastic lymphoma kinase (ALK) gene has been demonstrated to be rearranged, mutated or amplified in several haematological and solid tumors. Moreover, the use of ALK inhibitors has recently revolutionized the treatment of ALK-rearranged patients affected by non-small cell lung carcinoma. Herein we review the genetic alterations of ALK in melanocytic neoplasms described in literature, focusing on their potential diagnostic and predictive role. The Authors reviewed the pertinent literature through research on PubMed server was performed typing the terms "ALK", "Anaplastic lymphoma kinase", "ALKATI", "Melanoma", "Spitz", "Spitzoid". ALK translocations were demonstrated in melanocytic neoplasms, particularly in acral melanoma and spitzoid tumors. ALKATI was described in primary and metastatic melanoma, indicating its early occurrence in oncogenesis, with varying immunohistochemical expression of the protein. The identification of the specific type of ALK mutations could be interesting for planning biologic therapy of melanoma patients. Further studies are needed to evaluate the possibility to introduce an ALK-targeted therapy in patients affected by malignant melanoma.