Malignant melanoma in children and young adults: effect of diagnostic criteria on staging and end results.

Since the entity of "juvenile melanoma" was first described, many pathologists have been reluctant to diagnose malignant melanoma in childhood by pathologic criteria alone. In this series of 125 cases, pathologic criteria are used to distinguish malignant melanoma of childhood from spindle and epithelioid nevus. Among the patients reviewed, 110 cases (86%) occurred between ages 13 and 20 years, and 15 cases (14%) in children under 12. There were 60 males (54%) and 50 females (46%) in the older age group, and six males (41%) and nine females (59%) in the childhood group. In the 13 to 20 age group, there were 24% head and neck primary melanomas, 38% truncal primaries, 30% limb primaries, and 7% indeterminate, as opposed to 35% head and neck, 23% truncal, and 41% limb in the group under 12. In the 13 to 20 year group, 66% were stage I, 11% stage II, 12% stage III, 2% stage IV and 7% indeterminate while in the 12 and under group, 76% were stage I, 12% stage III, and 12% stage IV. Mortality rates were 49% for the 13 to 20 year group and 60% for the 12 and under group.