Adenocarcinoma of the hepatic duct junction. A reappraisal of the histologic criteria of malignancy.

The morphologic distinction between benign and malignant sclerotic processes involving the hepatic duct junction may be difficult. To determine reliable histologic criteria of malignancy, the authors reviewed 18 cases of clinically suspected adenocarcinoma of the hepatic duct junction (Klatskin tumor) retrieved from our autopsy and surgical pathology files over the last decade. The lesions were compared histologically to a variety of benign sclerotic biliary duct lesions, including four cases of primary sclerosing cholangitis (PSC) treated surgically over the same time period. A diagnosis of malignancy was confirmed histologically in 16 suspected Klatskin tumors, based on the presence of severe cytologic atypia (13) and/or perineural invasion (15). The tumor patients averaged 59 years of age with a male to female ratio of 2:1. Patients with segmental tumor resection and postoperative radiotherapy have survived as a group 6 months longer (average, 15.7 months) than those treated with drainage procedures alone (average, 9.5 months) (P less than 0.005), but have had extensive postoperative morbidity. In all the surgical specimens, tumor was present at one or more margins of resection. Primary sclerosing cholangitis patients were younger (average, 31 years of age) with a similar male predominance, but with a strong history of inflammatory bowel disease. All are alive up to 6.5 years since disease onset, with comparatively little postoperative morbidity. Two clinically diagnosed Klatskin tumors were not confirmed on histologic review. Both patients are alive at 1 and 3.5 years following onset of disease, having experienced little postoperative morbidity. Data indicate that Klatskin tumors are relatively aggressive malignancies, distinct from more indolent benign sclerotic disease, but occasionally mimicked by it clinically. Malignancy can be diagnosed histologically with adequate tissue sampling, thereby facilitating clinical decisions regarding radiotherapy or other palliative surgical procedures.