Rhabdomyosarcoma of the breast: Report of a rare malignancy.

Rhabdomyosarcoma (RMS) is an uncommon type of soft-tissue malignancy which mainly influences children. RMS rarely occurs in breast and little of the clinical behavior and treatment strategies were reported. Here, we describe a case of adult female patient with breast RMS. A 34-years-old Chinese woman visited to our hospital complaining palpable mass in her left breast. Seven months ago, the patient was diagnosed as lymphocytic mastitis and received surgical excision in the left breast. Five months later, she noticed a palpable mass again in the left breast. Ultrasonography suspected a malignant lesion and a diagnosis of RMS was made after segmental mastectomy and immunohistochemical staining. Therapy consisted of mastectomy and following neoadjuvant chemotherapy. The patient has remained disease free 30 months post-operatively. We should consider RMS when we see a breast mass. Tissue biopsy and immunohistochemical staining are recommended for diagnosis of RMS in young women. Oncologists should take immediate and active treatment on RMS.