RESUMEN
A variety of malignancies have been documented to arise within congenital melanocytic nevi (CMNs).Although the most frequent malignancy arising within a CMN is melanoma, the association betweenrhabdomyosarcoma and CMN has rarely been documented. We report a 4-month-old girl presentedwith ulcerated nodule overlying a giant CMN at the posterior back that exhibited rapid growth.Biopsy of the nodule revealed embryonal rhabdomyosarcoma in association with CMN. She receivedchemotherapy with vincristine and actinomycin D. This the first case of rhabdomyosarcoma associatedwith giant CMN reported in our local setting. Clinicians must consider rhabdomyosarcoma as one ofthe differential diagnosis in patients presenting with ulcerated nodules on giant CMN.