In neuroendocrine differentiated breast cancer, the coexistence of both neuroendocrine and exocrine components may raise some uncertainty about the best clinical approach to adopt. We describe the case of a patient with neuroendocrine differentiated breast carcinoma with lung metastases, who experienced a partial response after epirubicin chemotherapy. During subsequent maintenance hormone therapy with letrozole, plasma chromogranin A was consistently elevated even though CT showed disease stabilization. The patient was scheduled for surgery and radical resection was performed. She is still alive and disease free after over 37 months. Anthracyclines are effective in the treatment of neuroendocrine differentiated breast carcinoma. Surgical resection of metastatic lesions can lead to a durable disease-free status. Serial evaluation of circulating chromogranin A is useful in the follow-up of these patients.