Primary Hepatic Adenosquamous Carcinoma Associated with Primary Sclerosing Cholangitis

Introduction: Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disorder characterized by multiple fibrotic strictures of the bile duct. More than 40% of deaths in PSC patients are related to malignant tumors, including cholangiocarcinoma. Primary hepatic adenosquamous carcinoma (ASC) is a rare subtype of cholangiocarcinoma containing adenocarcinoma (AC) and squamous cell carcinoma (SCC) components, with a poorer prognosis than other cholangiocarcinomas. We report the first case of a hepatic ASC in a patient with PSC. Case Report: A 28-year-old man was referred for diagnosis and treatment of a liver abscess suspected by contrast-enhanced computed tomography (CE-CT). He had a history of ulcerative colitis and PSC. Abdominal CE-CT revealed a 60-mm-diameter ring-shaped mass with central necrosis in the left lobe. Magnetic resonance imaging demonstrated a poorly circumscribed low-signal-intensity mass in T1-weighted imaging and a high-signal-intensity mass with a scattered low-signal-intensity area in T2-weighted imaging. Abdominal ultrasonography showed a hypoechoic component with a diffuse hyperechoic area in the tumor. Ultrasound-guided biopsy and histological examination showed tumor cells with both squamous and glandular differentiation. Left lobectomy was performed. Microscopic examination revealed 2 components, including moderately differentiated AC and well-differentiated SCC. The final diagnosis was hepatic ASC. Conclusion: This is the first reported case of hepatic ASC in a patient with PSC. Patients with PSC should be recognized as being at a risk of not only general cholangiocarcinoma, hepatocellular carcinoma, and metastatic liver tumor, but also ASC.