Background : Adenosquamous carcinoma of the biliary tract is a rarer histopathologic subtype. This tumor has been described as an infiltrative bile duct cancer composed of a squamous component and a glandular component and is notorious for its poor prognosis. Adenosqamous carcinoma of Klatskin’s tumor is a very rare.

Methods : We report here on a case of a patient with adenosquamous carcinoma of Klatskin’s tumor.

Results : 71-year-old man was admitted to our hospital because of jaundice. The abdominal computed tomography and magnetic resonance cholangiopancreatography revealed a mass with wall thickening and luminal stenosis of the common hepatic duct (CHD). These findings were compatible with Klatskin tumor (Bismuth type I). The operation findings showed a 2.5 cm sized mass in the CHD. Frozen biopsy of distal CBD showed the malignant cells, and proximal CHD showed negative. Tumor was directly invaded right hepatic artery. We performed a hepaticopancreaticoduodenectomy. The histopathologic finding showed adenosquamous carcinoma. Regional lymph node metastasis occurred from direct invasion by the squamous cell carcinoma component. After surgery, External radiotherapy and chemotherapy (CCRT) were done.

Conclusions : Histopathologically, Adenosquamous carcinoma of the bile duct is characterized by greater local aggressiveness than their CT findings.