An Unusual Destination: Neuroendocrine Carcinoma Arising in the Breast, an Uncommon and Aggressive Entity

Neuroendocrine-differentiated breast carcinoma is an uncommon and challenging subtype of breast cancer, with aggressive clinical behavior. Owing to the limited number of reported cases and the lack of standardized treatment guidelines, its clinical presentation, natural history, and optimal management remain poorly defined, particularly in the metastatic setting. Herein, we report the case of a 66-year-old woman who was referred to our department for the management of a de novo metastatic small-cell neuroendocrine carcinoma of the breast.