[A Case of Synchronous Bilateral Breast Cancer with Apocrine Feature].

The patient, a 79-year-old woman, noticed a lump in her left breast, prompting her visit to our hospital. A mass approximately 20 mm in size was palpated in the left A region. Mammography showed a spiculated mass in the left MIO region, while breast ultrasonography revealed an irregularly shaped hypoechoic mass in the left A region, as well as a hypoechoic area in the right C region. Puncture aspiration cytology of both lesions indicated malignancy. Bilateral partial mastectomy and left sentinel lymph node biopsy were performed. The pathological examination revealed apocrine carcinoma in the left and ductal carcinoma in situ with an apocrine feature in the right breast.