Asynchronous bilateral neuroendocrine breast carcinoma-a case report

We report a case of asynchronous bilateral neuroendocrine breast carcinoma. The patient was a 49-year-old woman presenting with a bloody nipple discharge from the right breast. We suspected intraductal papilloma and performed a microdochectomy. A pathological analysis of the resected specimen confirmed the diagnosis as neuroendocrine carcinoma. The tumor was positive for estrogen receptor, progesterone receptor, chromogranin A, and synaptophysin, but negative for the HER2/neu marker. The Ki-67 labeling-index was 40%. As the tumor margin was positive, breast-conserving surgery plus level II axillary lymph node dissection was performed. After surgery, radiotherapy (total dose of 50 Gy) was administered for treating residual breast involvement. Adjuvant hormonal therapy was performed for 5 years. Ten years after surgery, ultrasonography revealed a 12 mm irregular hypoechoic mass in the left breast. The mass was diagnosed as a solid tubular carcinoma based on core needle biopsy findings. Subsequently, we performed breast-conserving surgery. The pathological diagnosis was a neuroendocrine carcinoma, and the tumor was positive for estrogen receptor, progesterone receptor, chromogranin A, synaptophysin, and CD56, but negative for the HER2/neu marker. The Ki-67 labeling-index was 50%. We report our experiences with a rare case of asynchronous bilateral neuroendocrine breast carcinoma. In this case, ultrasonography was a useful modality for detecting both the lesions.