We describe an unusual case of infiltrating ductal carcinoma, not otherwise specified, containing numerous benign stromal osteoclast giant cells (OGCs). Macroscopically, the tumor appeared as a well-outlined dark brown mass and was initially interpreted as a benign lesion on the mammograms. OGCs were uniformly distributed in the tumor and were found in vascularized, hemorrhagic stroma often abutted on the nests of tumor cells. Electron microscopy supported a histiocytic origin of the OGCs, but immunohistochemistry failed to confirm the observation. The patient was alive and well 30 months following the operation. A review of the literature concerning breast carcinoma with OGCs is also presented.