A Case of Metastatic Breast Tumor Originated from Rhabdomyosarcoma of the Anal Canal

Abstract

Metastatic rhabdomyosarcoma in the breast is an uncommon event. We report a case with breast metastasis from rhabdomyosarcoma in a 16-year-old girl. At the age of 14, she was diagnosed with alveolar type rhabdomyosarcoma of the anal canal. At her initial presentation, a bone-marrow metastasis was observed. She underwent chemo-radiation therapy followed by bone marrow transplantation from a sibling. These therapies resulted in a complete remission, but 27 months after the bone marrow transplantation, she noticed an enlarging right breast mass and was referred to our department. On physical examination, the tumor was elastic-soft, 4.0×3.0 cm located in the upper outer quadrant area of the right breast and a core needle biopsy was performed for the histological diagnosis. The tumor turned out to be a metastatic mammary tumor originated from rhabdomyosarcoma that showed positive immunohistochemical staining of desmin and myogenin. This patient underwent right mastectomy and axillar lymph node dissection.
We report a case of metastatic breast tumor that originated from rhabdomyosarcoma of the anal canal with some review of the literature.