Bone marrow metastasis of malignant melanoma in childhood arising within a congenital melanocytic nevus.

BACKGROUND: Malignant melanoma in childhood is infrequent and can arise within congenital melanocytic nevi. Spread of malignant melanoma to the bone marrow, especially in children, is extremely rare.

METHODS AND RESULTS: Reported is a case of a 5-year-old boy with a congenital large melanocytic nevus of the head and neck who presented with a short history of low back and leg pain, fever and cervical lymphadenopathy. Despite regular follow-up by a dermatologist and plastic surgeon and repeatedly negative histology of previous partial excisions, diffuse bone marrow infiltration with malignant melanoma was diagnosed. The primary site was identified in the post-excision area. The disease progressed rapidly on ipilimumab immunotherapy and led to death at four months from the diagnosis.

CONCLUSION: Surveillance is indispensable in children with a predisposition to melanoma and nonspecific symptoms such as bone pain, gait impairment or cytopenia, should always be taken into account.