Malignant melanoma in children--case presentation and statistical analysis

Malignant melanoma is a well documented but rare occurrence in children. We reported a case of a 10-month-old girl with malignant melanoma arising in a giant congenital nevocellular nevus. A giant mole on the lumbar and gluteal legion had been present since birth. Six month later, a nodular legion within the giant nevus started to growth slightly. The skin nodule were widely excised and grafted. Histological examination showed a malignant melanoma. The tumor located only in dermis. An enlarged lymph node of her left inguinal was removed. The histology revealed metastases from the melanoma. She died of metastases eight months after removal of the primary tumor. To our knowledge, only 37 documented cases of malignant melanoma in children under fifteen years of age have been previously reported, to which we add our case. In Japan, two-thirds of childhood melanomas arise de novo, which are clinically and biologically analogous to adult melanomas. The other third arises in large congenital nevocellular nevus which likely lead to death within two to three years of diagnosis. A majority of at least half of malignant melanoma in large congenital nevocellular nervus arise in children under 10 years of age. ALM types of malignant melanoma which are common in adult are rare in childhood melanomas.