Malignant melanoma in children.

BACKGROUND

While significant risk factors for malignant melanoma may initially develop or are first seen in childhood, the actual occurrence of this neoplasm in prepubertal children is uncommon.

METHODS

A retrospective study of malignant melanoma in Puerto Ricans up to 16 years of age occurring from 1973 to 1990 was carried out by identifying those cases in the Puerto Rico Cancer Registry.

RESULTS

A total of seven cases were found consisting of three boys and four girls with ages ranging from 22 months to 16 years and comprising 0.94% of the total melanomas. In three of the seven cases, there was a history of a previously existent small congenital melanocytic nevus on the area. Three cases were Clark's level I, two level II, and in two cases with proved metastatic disease, Clark's level of invasion were not reported. Those cases with Clark's level I and II had a 100% 5-year survival.

CONCLUSIONS

Although rare, malignant melanoma in children can be as aggressive as in adults. Among the known factors predisposing to malignant melanoma, three out of seven cases developed within a small congenital nevus, two of which occurred during the first decade of life. Due to the rarity of this event in our population, it appears unreasonable to excise all small congenital nevi during the first decade of life. Even for those who advocate excision of all small congenital nevi, the evidence at present suggests that such small nevi very rarely undergo malignant change before puberty and therefore a policy of observation in childhood and offering excision around the time of puberty is perfectly logical.