A Case of Primary Malignant Melanoma of the Bile Duct

We report a rare case of primary malignant melanoma of the common bile duct. A 55-year-old man reporting general fatigue and icterus was found on MRCP to have a tumor in the middle common bile duct. Since we could not determine malignancy from bile juice cytology, we diagnosed middle common bile duct cancer due to the tumor's large size. Macroscopic findings in resection of the common bile duct and hepaticojejunostomy (Roux-en Y) showed a black tumor about 3cm in diameter. Histopathology and immunohistochemistry showed the tumor to be malignant melanoma. To determine whether the tumor was primary or metastatic, we found FDG-PET to be useful. The tumor had originated in the common bile duct, and FDG-PET detected multiple liver metastasis. Due to the lack of reports on chemotherapy for primary malignant melanoma of the bile duct, we tried dacarbazine, nimustine hydrocholaride, and vincristine sulfate (DAV), but to no avail. The patient died 4 months after surgical resection.