Ancillary testing for melanoma: current trends and practical considerations

The diagnosis of melanocytic lesions is aided by ancillary testing, but clinical inspection with the histomorphological assessment on biopsy remains sufficient in most cases. Immunohistochemistry and molecular studies have proven useful for diminishing the pool of histomorphologically borderline lesions, and sequential testing may further improve overall diagnostic performance, but these assays should be used in a stepwise fashion if at all. Ancillary tests vary based on their technology, performance, and practical considerations, including but not limited to the specific diagnostic question, cost, and turn-around time, which impact test selection. This review examines currently used ancillary tests for the purpose of characterizing melanocytic lesions. Both scientific and practical considerations are discussed.