Acrolentiginous melanomas

Abstract

Acrolentiginous melanoma (ALM) accounts for 5% of all melanoma types. Even though it occurs in all ethnic groups, a preference in dark skin has been observed over the time. A lack of typical alarming signs still results in late diagnosis. Recently, distinct molecular characteristics have been defined for melanoma by Bastian et al. ALM and mucosal melanoma are suggested to show aberrations in the cKIT gene. It is involved in tumorigenic growth signaling. cKIT tyrosine kinase receptor has been yet proven as a successful target in chronic myeloid leukemia and in gastrointestinal stromal tumors. Histologically, mucosal melanomas show ALM characteristics. Specific staining with proliferating cell nuclear antigen for cutaneous melanoma in general and cKIT protein expression for ALM and mucosal melanomas in particular, can help to identify this tumor in comparison with benign melanocytic lesions. Genetic aberrations do not necessarily correlate with the KIT protein expression. Several studies applying small molecule inhibitors such as Imatinib have been performed in patients with melanoma. Single-patient cases with known cKIT mutations revealed impressive clinical response.