A case of squamous cell breast carcinoma is presented. The patient was 31-year old woman with a complaint of a right breast mass. The tumor was found to measure 7.0 x 8.0 cm without any inflammatory signs, and was associated with a bloody nipple discharge. Lymph-node metastases of the ipsilateral axillary and supraclavicular nodes were noted, and metastasis to the fifth lumbar vertebrae also was seen. Because of a diagnosis graded T4bN3M1, stage IV, an extended radical mastectomy was performed. Histologically, the major portion of this tumor consisted of a squamous cell carcinoma with a minimal component of adenocarcinoma and accompanying keratinization. The patient died of this cancer 5 months after the operation.