Malignant carcinoid tumor of the cystic duct: a rare cause of bile duct obstruction.

BACKGROUND: Carcinoid tumors of the extrahepatic biliary tree are extremely rare malignancies, accounting for 0.2%-2% of all gastrointestinal carcinoid tumors, while carcinoids of the cystic duct are an uncommon entity and an extremely unusual cause of bile duct obstruction.
METHODS: After an extensive literature review, we retrospectively analysed 61 cases of carcinoid tumor of the biliary tree as well as one additional case of a 60-year-old female with symptoms and laboratory/imaging examination findings compatible with those of a malignant biliary tract obstruction. At laparotomy, resection of the gallbladder and common bile duct was performed. Histological study revealed a well-differentiated neuro-endocrine carcinoma of the cystic duct. The patient remained disease-free at 16 months.
RESULTS: Our presentation is the seventh case reported in the world literature. Compared to cholangiocarcinoma, analysis of the reviewed group indicates an increased incidence of extrahepatic carcinoid tumors in younger persons along with a slight female predominance. Statistically, the most common anatomic location is the common bile duct, followed by the perihilar region and the cystic duct. Jaundice is the most common finding. Curative surgery was realized in the majority of cases and long-term disease-free survival was achieved when surgery was curative.
CONCLUSIONS: Carcinoid tumors obstructing the biliary tree are extremely difficult to diagnose preoperatively, and nearly impossible to differentiate from non-neuroendocrine tumors. As surgery offers the only potential cure for both biliary carcinoids and cholangiocarcinoma, we recommend aggressive surgical therapy as the treatment of choice in every case of potentially resectable biliary tumor.