A rare case report of a primary large-cell neuroendocrine carcinoma of the breast with coexisting Paget disease.

Neuroendocrine carcinomas are malignancies deriving from neuroendocrine cells existing in various sites of the body, most commonly in the lungs and gastrointestinal tract. Primary neuroendocrine carcinomas of the breast are extremely rare, and their diagnosis is confirmed by positive neuroendocrine markers. We describe a case of a 46-year-old woman with a palpable mass in her left breast for the previous 3 months. The tumor was resected and a primary large-cell neuroendocrine tumor of the breast was confirmed by histopathologic examination. Paget disease of the nipple was noted as well.