Bilateral Metachronous Breast Carcinoma: A Rare Case Report.

The occurrence of bilateral breast cancer is rare. A second primary in the contralateral breast can either be synchronous or metachronous. Lobular carcinoma of the breast is known for its multicentricity and bilateral spread. The synchronous mixed pattern of carcinoma of the breast has also been reported in the same breast. The family history of breast carcinoma, estrogen receptor negativity, and human epidermal growth factor receptor-2 positivity are risk factors for the development of contralateral breast malignancy. In metachronous, bilateral breast cancer (MBBC) usually a single histological variant is seen at different time periods. However, we report a rare case of MBBC in a 66-year-old female patient with positive family history who had infiltrating lobular carcinoma (ILC) in the left breast followed by infiltrating ductal carcinoma in the right breast after a span of 2½ years, even after undergoing modified radical mastectomy with adjuvant chemotherapy followed by hormonal therapy for ILC of left breast.