Abstract
We herein present a rare case of neuroendocrine carcinoma originating from the cystic duct. A 76-year-old male with jaundice was referred to our hospital for further examination and possible surgery. Under a strong suspicion of distal bile duct cancer, he underwent pancreaticoduodenectomy. Macroscopically, the tumor had a pedunculated polypoid appearance, originated in the cystic duct, and prolapsed into the common bile duct. Microscopically, the tumor was composed of small cells with a high N/C ratio presenting solid growth. An immunohistochemical study of the tumor showed positive reactivity for chromogranin A and synaptophysin, and a Ki-67 index of 60%, thus indicating neuroendocrine carcinoma. In addition, atypical epithelium with severe dysplasia was found in the cystic duct around the tumor. He did not receive adjuvant chemotherapy, but has had no sign of recurrence for 24 months after surgery.
