Abstract
Endocrine cell carcinoma rarely occurs in the bile duct, and cases originating in the cystic duct are exceedingly rare ; the case presented is only the fourth to be reported. The patient was a 58-year-old woman in whom a 3-cm, polypoid, elevated lesion with a well-defined border and smooth surface was observed in the middle bile duct. Since bile duct carcinoma was suspected, bile duct resection and D2 lymph node dissection were performed. The tumor was yellow, had the appearance of a pedunculated polypoid mass with a smooth surface, and originated in the cystic duct. Because it had prolapsed into the common bile duct, it appeared on imaging to be a bile duct tumor. Alveolar proliferation of small, round tumor cells having a high N/C ratio and rich in chromatin was seen, and positive results were obtained for chromogranin A and synaptophysin staining. Karyokinesis was seen in many cells, and the Ki67-positive rare was 50%. Based on the above findings, the patient was diagnosed with endocrine cell carcinoma. Endocrine cell carcinoma of bile duct origin has a poor prognosis due to early hematogenous metastasis, particularly liver metastasis. No chemotherapy has been established for this disease, and responses are often poor. IP therapy was given as adjuvant chemotherapy, and the patient remains recurrence-free 19 months after surgery.
