Breast metastases in children with rhabdomyosarcoma.

Of 108 consecutively diagnosed patients with rhabdomyosarcoma, seven subsequently developed clinically evident metastatic tumors of the breast. These patients were unusual in that all had primary tumors located on an extremity or the buttock, and six of the seven tumors had alveolar histology. Sex distribution and age of the patients indicated that the physiologic state of the breast was an important determining factor in the development of such metastases.