Pathological characteristics of 6 advanced, sporadic biliary tract cancer patients.

U/S = Ultrasound.*NST: No special type.**Rare gland formation with expression of cytokeratin, polyclonal CEA, and MOC-31.All were adenocarcinomas of no special types and high grades as defined by the World Health Organization Classification of Tumors of the Digestive System (Lyon 2000). Degree of differentiation is based on the percentage of glands (defined as having visible lumens by visual estimate) as follow: 95% or more glands-well differentiated, 40–94% glands-moderately differentiated, 5–39% glands-poorly differentiated,