Definition and diagnosis of early cancer of the biliary tract.

From the study on correlation between the depth of cancer invasion and the results of surgery, early cancer of the biliary tract may be defined as cancer cell invasion limited to the mucosal or muscularis propria in the case of carcinoma of the gallbladder, and to the mucosal or fibro-muscular layer in the case of carcinoma of the bile duct. With few exceptions, these tumors had no lymph node metastasis, venous invasion, perineural infiltration or involvement of the lymphatic vessels. Since the cumulative 5-year survival rate was 100% after resection of early cancer, the choice of surgical procedures was considered to be extended cholecystectomy for early cancer of the gallbladder, and the standard radical resective operation for early cancer of the bile duct. An accurate diagnosis was not made preoperatively in most cases of early cancer of the biliary tract. The diagnostic approach is discussed, including the recently developed imaging modalities, such as endoscopic ultrasonography and percutaneous transhepatic cholecystoscopy or cholangioscopy.