A case of lipid-secreting carcinoma in the right breast of a 78-year-old Japanese woman is reported. Light microscopy revealed solid alveolar proliferation in the majority of tumor cells, which had abundant foamy cytoplasm. A variable amount of neutral lipid was identified in the cytoplasm of the tumor cells by Sudan III staining and electron microscopy. This case is reported along with a discussion of other cases of lipid-secreting or lipid-rich carcinoma that have been reported in the international literature.