Some breast neoplasms are classified as primary neuroendocrine carcinomas because they are positive for neuroendocrine markers. Although neuroendocrine carcinomas can originate from various organs of the body, primary neuroendocrine carcinomas of the breast are extremely rare. The diagnosis of primary neuroendocrine carcinoma of the breast can only be made if nonmammary sites are confidently excluded or if an in situ component can be found. Here we report a primary large-cell neuroendocrine carcinoma (LCNL) involving the left breast. Breast ultrasonography revealed a lobulated, heterogeneous, low-echoic mass in the left breast, and the lesion ap-peared as a well-defined, highly-enhancing mass on a chest computed tomography scan. Ultrasound-guided core needle biopsy was performed on the mass, and primary LCNC was confirmed by histopathologic examination.
Adult ; Breast Neoplasms/*diagnosis/pathology/ultrasonography ; Carcinoma, Large Cell/*diagnosis/pathology/radiography ; Carcinoma, Neuroendocrine/*diagnosis/pathology/radiography ; Diagnosis, Differential ; Female ; Humans ; Tomography, X-Ray Computed

Neuroendocrine tumors are usually found in the ileum, appendix, rectum, colon and stomach. Ampullary neuroendocrine tumor is extremely rare and only a few cases of neuroendocrine carcinoma of the minor papilla have been reported. The preoperative diagnosis is very challenging because either asymptomatic or manifests as nonspecific abdominal pain. The tumor is relatively small and located at the deep mucosa and submucosa. Endoscopy with deep biopsy, endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography are good diagnostic tools. The best therapeutic choice is surgery. We report an unusual case of a 55-year-old woman who underwent endoscopy as part of a regular health checkup and was diagnosed a neuroendocrine carcinoma in the minor papilla, which was successfully resected by pancreaticoduodenectomy.
Carcinoma, Neuroendocrine/*diagnosis/pathology/ultrasonography ; Duodenal Neoplasms/*diagnosis/pathology/ultrasonography ; Duodenoscopy ; Female ; Humans ; Middle Aged ; Neoplasm Staging ; Pancreaticoduodenectomy ; Tomography, X-Ray Computed