Unusual or prominent calcifications found on screening mammography may prompt additional radiologic and clinical work-up given the possible association with pre-malignant lesions, other high-risk lesions, or malignancies. Osseous metaplasia (OM) of the breast, also referred to as metaplastic ossification or heterotopic bone formation, is an uncommon finding that may present as radiographic calcification. There are isolated case reports of OM associated with benign or malignant tumors of the breast, as well as with a variety of nonneoplastic conditions. We report 2 cases of OM in the breast associated with a hemangioma and review the relevant literature. To the best of our knowledge, these are the first reported cases of this association in the breast.

Unusual or prominent calcifications found on screening mammography may prompt additional radiologic and clinical work-up given the possible association with pre-malignant lesions, other high-risk lesions, or malignancies. Osseous metaplasia (OM) of the breast, also referred to as metaplastic ossification or heterotopic bone formation, is an uncommon finding that may present as radiographic calcification. There are isolated case reports of OM associated with benign or malignant tumors of the breast, as well as with a variety of nonneoplastic conditions. We report 2 cases of OM in the breast associated with a hemangioma and review the relevant literature. To the best of our knowledge, these are the first reported cases of this association in the breast.

Anastomosing hemangioma (AH) is an unusual benign vascular lesion that commonly occurs in the kidney and genitourinary tract. We report a case of AH in a 49-year-old woman presenting as a mass in the breast, a site which, to the best of our knowledge, has not been previously documented in the English literature. Microscopic examination of the mass revealed a well-demarcated proliferation of anastomosing vascular spaces lined by bland endothelial cells, with focal hobnailing and scattered intravascular fibrin thrombi. No mitotic activity was observed and the Ki-67 proliferative index was low. These features were interpreted as AH, a lesion that may be difficult to distinguish from low-grade angiosarcoma or other benign vascular lesions of the breast which may demonstrate anastomosing channels.Due to the presence of atypical histologic features which can raise suspicion for angiosarcoma on biopsy, complete excision of these lesions is recommended for optimal treatment.