The classification of malignant melanoma, its histological reporting and registration: a revision of the 1972 Sydney classification.

A group of pathologists with an interest in malignant melanoma met in Sydney in 1982 to update the classification of melanoma formulated in Sydney in 1972. The group recommended that malignant melanoma be classified as follows: malignant melanoma with an adjacent component of superficial spreading type, malignant melanoma with an adjacent component of lentigo maligna type, malignant melanoma with an adjacent component of acral lentiginous type, malignant melanoma with an adjacent component of mucosal lentiginous type, malignant melanoma with no adjacent component, malignant melanoma of unclassifiable histogenetic type. The data recorded in the surgical pathology report should include: diagnosis of primary malignant melanoma, histogenetic classification, presence/absence of ulceration, micrometer-measured thickness, microanatomical level, mitotic rate/mm2, presence/absence of vascular invasion, presence/absence of regression, completeness of resection. The recommendations for the examination of specimens and the recording of data for research purposes and for tumour registries are described.