Melanoma involving the surgical scar following surgery and craniospinal irradiation for childhood medulloblastoma: case report and literature review

Abstract

Patients with childhood cancer are at increased risk of developing melanoma as a secondary malignancy. It is unclear whether this risk is related to underlying patient predisposition or secondary to treatment effect. We report a case of a 43-year-old male with a history of childhood medulloblastoma at the age of 13 treated with surgery and craniospinal irradiation who presented with an enlarging occipital mass and contiguous, cutaneous, ulcerated nodule. The nodule appeared to arise within the patient’s occipital surgical scar. Imaging revealed a large mass in the posterior neck soft tissues with associated lytic destruction of the occiput and C1 vertebrae. Biopsy was consistent with melanoma, epitheliod and small cell types. No other sites of disease or cutaneous lesions were identified. Despite aggressive therapy with radiation therapy and chemotherapy, the lesion progressed and the patient died of complications of obstructive hydrocephalus. It is hypothesized that this patient developed melanoma as a result of his radiation therapy exposure or that tumor arose de novo in the surgical scar tissue. The presentation of the melanoma in this case and the potential etiologies are unique.