[Parallel furrow pattern in acral melanoma: biopsy processing technique can affect histological diagnosis].

Actas Dermosifiliogr. 2009;100:615-34 626 some forms of brain tumor; although such outcomes have not been demonstrated for melanoma. The cells of retinoblastoma, melanoma and dysplastic nevus are derived from the neural crest. There are authors who postulate that patients with retinoblastoma and dysplastic nevus syndrome have increased genetic susceptibility to melanoma due to a primary anomaly in the neural crest. The association between retinoblastoma and melanoma is a controversial issue potentially dependent upon genetic predisposition or the forms of treatment received. Patients with retinoblastoma have an almost 10-fold greater risk of suffering from melanoma than those with no history of retinoblastoma, especially in cases of bilateral or hereditary types. Consequently, close follow-up of these patients is vitally important, especially in patients with associated dysplastic nevus syndrome.