Case of breast cancer with endocrine differentiation

An 89-year-old woman presented with a chief complaint of induration in the left breast persisting for 1 month. Core needle biopsy of the lesion showed invasive breast cancer. Therefore, we diagnosed the lesion as left breast cancer and performed a modified mastectomy. On the immunohistochemical study, the tumor was positive for synaptophysin and positive in part for chromogranin-A and carcinoembryonic antigen. Therefore, we diagnosed the lesion as breast cancer with endocrine differentiation. We report the clinical and pathological features of this disease herein.