Histological Classification of Tumours of the Gallbladder and Extrahepatic Bile Ducts.- Definitions and Explanatory Notes.- Epithelial Tumours.- Endocrine Tumours.- Non-epithelial Tumours.- Miscellaneous Tumours.- Tumour-like Lesions.- TNM Classification of Tumours of the Gallbladder and Extrahepatic Bile Ducts.