Multicentric Neuroendocrine Carcinoma of the Breast Presenting with Multiple Osteolytic Bone Metastases.

An uncommon subtype of breast cancer, primary neuroendocrine carcinoma of the breast (NECB), usually presents as a single nodule arising in the breast tissue. Distant metastases at presentation are rare. Optimal management of advanced disease is still debated, given the lack of evidence stemming from clinical trials. We describe a patient who presented with clinically aggressive, multicentric NECB with multiple metastatic lytic bone lesions. Ihe disease responded to systemic therapy with an oral aromatase inhibitor and monthly biphosphonate infusions. We further review the existing literature on this intriguing clinicopathologic entity.