This report describes a patient with mesocolic leiomyosarcoma, initially treated by excisional surgery. One year later the patient developed breast and hepatic metastases. To our knowledge, metastasis of leiomyosarcoma to the breast has not been previously reported in the literature. The discussion covers unusual sites for metastases of primary leiomyosarcomas and those tumors that most commonly give rise to breast metastases. Certain rare primary tumors of the breast related to the family of sarcomas are also brought to the attention of the reader. These may or may not have malignant characteristics. In the light of the differences in prognosis and treatment, recognition and precise diagnosis is of importance.