CCND1 copy number increase and cyclin D1 expression in acral melanoma: a comparative study of fluorescence in situ hybridization and immunohistochemistry in a Chinese cohort.

High-level increase in the CCND1 copy number can induce high cyclin D1 protein expression in acral melanomas. However low-level increase and normal CCND1 copy number have no obvious correlation with protein expression. Cyclin D1 IHC cannot serve as a surrogate for CCND1 FISH in acral melanomas.