This is a classification of tumours and tumour-like lesions of the gall- bladder and extrahepatic bile ducts, including the ampulla of Vater. Although most of the lesions are found in all three sites, variations in frequency of the histological types occur and will be noted. The incidence of carcinoma of the gallbladder varies in different parts of the world. Variation is also found in different ethnic groups within the same country. In the United States, for example, carcino- ma of the gallbladder is more common in American Indians than in Caucasians or in Blacks; the rate among female American Indians is 21 per 100000 compared with 1.4 per 100000 among Caucasian fe- males. In Latin American countries, the highest rates are found in Chile, Mexico and Bolivia. In other countries, such as Japan, the inci- dence rates are intermediate between those of American Indians and those of Caucasians. Despite certain features in common, carcinomas of the gallblad- der and carcinomas of the extrahepatic bile ducts show a number of differences. Gallbladder carcinomas are usually associated with cholelithiasis and have a strong female predominance. In contrast, extrahepatic bile duct carcinomas are seen less often, occur in both sexes with equal frequency, are usually not associated with choledo- cholithiasis, produce early biliary obstruction, and are better differen- tiated histologically as a group. Moreover, they are seen in patients with primary sclerosing cholangitis and ulcerative colitis.

The current edition contains new information accumulated during the last ten years on tumours and tumour-like lesions of the gallbladder, extrahepatic bile ducts and Vaterian system. Because of the increasing number of laparoscopic cholecystectomies and Whipple procedures performed, surgical pathologists now have the opportunity to examine more cancer precursors, early cancers, and adenomas of the gallbladder, extrahepatic bile ducts and ampulla of Vater than previously. These lesions are discussed in detail and profusely illustrated. Likewise, lesions that closely simulate malignant neoplasms are also described and illustrated. Also included are the giant cell neoplasms and the gastrointestinal stromal tumours as well as the new subtypes of carcinomas such as large cell neuroendocrine carcinomas and adenocarcinomas with pyloric gland or foveolar phenotype. The role of immunohistochemistry in the diagnosis of a wide variety of neoplasms is emphasised as well. This book will be a great resource to practicing pathologists and students for years to come.