Introduction
Primary breast sarcomas are very rare, and primary breast osteosarcoma
(PBOS) is still far less common. To the best of our knowledge, less than
150 cases of PBOS have been reported by this time; however, based on
recent investigations, it is possible that even many of those cases were
not really PBOS and they were some variants of metaplastic breast
carcinoma. Indeed, they were considered as PBOS because of the lack of
conducting a comprehensive histological and immunohistochemical (IHC)
evaluation (1). Since there is no common consensus
regarding the management of this specific kind of malignancy, reporting
each case and its challenges could be helpful to provide more
information about this type of aggressive and poor prognostic tumor.