CONGENITAL ALVEOLAR RHABDOMYOSARCOMA WITH MULTIPLE SKIN METASTASES: Report of a Case

A rare case of congenital alveolar rhabdomyosarcoma revealing multiple skin metastases in a female neonate is reported. At birth, a ping-pong ball-sized tumor on the neck and a tumor the size of a little finger end on the chin were noticed. Then, multiple skin tumors over the whole body occurred soon after birth. A biopsied small skin tumor was at first interpreted as being compatible with metastatic congenital neuroblastoma. However, immunohistochemical and electron microscopic findings revealed positive immunoreactivity for myoglobin in a few tumor cells and the presence of a few rhabdomyoblasts among poorly differentiated tumor cells, resulting in a final diagnosis of alveolar rhabdomyosarcoma. Therefore, it should be emphasized that in cases of round cell tumor, immunohistochemical and ultrastructural studies are imperative in order to identify the tumor and differentiate it from other forms, including rhabdomyoblastoma, neuroblastoma, Ewing's sarcoma, malignant lymphoma, and small cell carcinoma.