Progress in melanoma histopathology and diagnosis.

This article reviews the main aspects of the histopathology of cutaneous melanoma with emphasis on recent advances in the morphological evaluation of these lesions. The limitations of morphology for the "so called" borderline lesions are briefly discussed, with a list of diagnostic criteria to help predict behavior for these challenging lesions. The prognostic factors are described with emphasis on the ones that are currently being used by the American Joint Committee on Cancer staging system. Ancillary tests, such as immunohistochemistry and molecular techniques, are also briefly touched upon as complimentary tools to help understand the biology of malignant melanoma. The conclusion is that an accurate morphological evaluation remains the most efficient approach to establish the diagnosis and predict behavior of this challenging neoplasm.