Breast Metastasis from Multiple Primary Rhabdomyosarcoma in Upper Extremity

We report a 16-year-old girl with a multiple primary rhabdomyosarcoma of right upper extremity who developed contralateral breast metastasis in her clinical course. She was diagnosed to have multiple primary rhabdomyosarcoma of the right upper extremity with lung metastasis one year prior to finding a mass in her left breast. The excisional biopsy of the breast mass confirmed metastatic rhabdomyosarcoma. Despite aggressive chemotherapy and subcutaneous total mastectomy, she developed a widespread bone and lung metastasis in few months and expired. Metastatic rhabdomyosarcoma of the breast is very rare but it should be considered in adolescent females with primary alveolar rhabdomyosarcoma, specially located on an extremity.