Malignant melanoma in a 12-year-old boy 17 months after completing hepatoblastoma treatment

BackgroundMelanoma is rare as a secondary malignant neoplasm among childhood cancer survivors.CaseWe report a case of a 12-year-old boy who developed malignant melanoma with systemic metastases 17 months after completing treatment for hepatoblastoma. The diagnosis was made unexpectedly based on a bone marrow examination. The patient did not respond to immune checkpoint inhibitor therapy and died 6 weeks after being diagnosed with melanoma. Whole-exome sequencing to examine 103 genes associated with cancer predisposition did not identify any germ-line variants.ConclusionThis case study provides a unique example of melanoma in a childhood cancer survivor following hepatoblastoma treatment but does not identify any candidate variant to link hepatoblastoma and melanoma.