A case of cystic duct carcinoma treated with surgery and adjuvant radiotherapy: a proposal for new classification.

Cystic duct carcinoma is a rare disease. We present the case report of a 63-year-old man with cystic duct adenocarcinoma. In this patient, we performed cholecystectomy and segmental resection of the bile duct with lymph node dissection. A histopathologic examination showed that the cystic duct was obstructed by a solid mass. It also revealed the presence of cystic duct adenocarcinoma with lymph node metastasis, where the tumor involved resection margins. We therefore decided on postoperative adjuvant radiotherapy for the prevention of local failure. The patient had an uneventful course, apart from a liver abscess. Nevertheless, he died with liver metastases 15 months postoperatively. Our case highlights the role of postoperative radiotherapy and the necessity of a new classification system based on the extent of tumor infiltration.