Rhabdomyosarcoma arising in a giant congenital melanocytic nevus.

We report the case of a 6-week-old girl who presented with a pedunculated embryonal rhabdomyosarcoma arising in a giant congenital melanocytic nevus (GCMN) on her lower back. There was no associated leptomeningeal involvement. The patient underwent surgical resection of the rhabdomyosarcoma at age 2 months, with subsequent chemotherapy consisting of actinomycin D and vincristine. No recurrences or metastases of tumor have been noted at 5 months of age.