A case of neuroendocrine tumor of the bile duct

• Published in: Tando Vol. 27; no. 1; pp. 118 - 123
• Main Authors: Kan, Hiromi, Fujimoto, Yoshifumi, Tokumo, Hironori, Nakamitsu, Atsushi, Daimaru, Yutaka
• Format: Journal Article
• Language: Japanese
• Published: Japan Biliary Association 2013
• Subjects: bile duct; neuroendocrine tumor; WHO classification
• ISSN: 0914-0077; 1883-6879
• DOI: 10.11210/tando.27.118

A female patient in her 60s presented at hospital with the principal complaint of nausea. Blood tests revealed jaundice and elevated hepatobiliary enzymes, and abdominal CT revealed an early stage tumor with strong contrast effect in the upper bile duct. ERCP showed stenosis in the upper to middle bile duct, with pronounced dilatation of the upstream bile duct. Re-examination of ERCP the following day showed a tumor shadow with a gentle slope, and a submucosal tumor was suspected. On oral cholangioscopy, most of the mass demonstrated the morphology of a submucosal tumor. Based on the above factors, the patient was pre-operatively diagnosed with submucosal invasion of cancer of the upper biliary tract, and an extrahepatic bile duct resection was performed. HE staining showed hyperplasia of small tumor cells with a high N/C ratio in a solid alveolar arrangement. Immunostaining findings were positive for chromogranin A and a diagnosis of neuroendocrine tumor (NET)-G2 was made based on the 2010 WHO classification. Bile ducts are an extremely rare primary site for neuroendocrine tumors, and as there are no other case reports in which the patient has been observed preoperatively via oral cholangioscopy, this case was considered very valuable.