The patient was a 36-year-old man who had received regular oral entecavir treatment for hepatitis B cirrhosis, which had been present for five years. This patient was recently admitted to the hospital with elevated alpha-fetoprotein. The patient had a family and genetic history of hepatitis B (his brother). A physical examination of the patient revealed no notable anomalies. Laboratory findings were as follows. Liver function biochemical parameters: total bilirubin, 49.3 μmol/L (normal, <23 μmol/L), direct bilirubin, 15.97 μmol/L (normal, <6.8 μmol/L) and indirect bilirubin, 33.33 μmol/L (normal range 1.71-13.68 μmoL/L). Muscle enzyme profile: aspartate aminotransferase, 50.7U/L (normal: 0-40 U/L), alanine aminotransferase, 373.92 U/L (normal: 9-50 U/L), alkaline phosphatase, 230.16 U/L (normal: 45-125 U/L), transglutaminase, 62 U/L (normal range: 11-50 U/L), total bile acids, 12.25 μmol/L (normal range 0.1-10 μmol/L) and glycocholic acid, 12.25 μmol/L (normal range 0-2.7 μmol/L). Tumor marker: alpha-fetoprotein, 461 ng/mL (normal range 0-8.1 ng/mL). Hepatic fibrosis combination analysis: hyaluronidase, 111.6 ng/mL and laminin, 9.84 ng/mL.
The liver appeared to have an uneven shape and a rough surface on CT imaging. Segments 5 and 6 of the liver revealed a hypodense mass that was approximately 63 mm × 90 mm in size, had an amorphous shape, and had ill-defined edges. On enhancement scan, the lesion showed mild to moderate heterogeneous enhancement in the arterial phase, and patchy and nodular hypoenhancing regions were detected within the lesion in the delayed phase. In the right branch of the portal vein, a cast-filling defect with little localized enhancement was visible. The splenic vein was thickened, and the spleen's volume was increased(Figure 1). In comparison to the liver, the lesion showed low signal intensity on MRI and T1-weighted imaging. The lesion appeared as a slightly uneven hyper signal on T2-weighted imaging, along with many nodules and bands of T2 hypointense signal. Diffusion-weighted imaging (DWI) also revealed severe diffusion limitation, and the lesions had unevenly elevated signals. Expression diffusion coefficient (ADC) mapping displayed low signals. The lesion displayed heterogeneous and more significant enhancement on magnetic resonance dynamic enhancement, and the delayed phase revealed branching nonenhancing shadows inside the lesion. The intra- and extrahepatic bile ducts were not significantly dilated. The right portal vein tumor thrombus showed a low signal on T1-weighted scans but a significant signal on T2-weighted images. The tumor thrombus showed annular expansion in the arterial stage and concentric filling in the portal vein stage and the delayed stage (Figure 2). According to the patient's history of cirrhosis, clinical symptoms, and imaging signals such as splenomegaly and a portal vein cancer thrombus, the probability of hepatocellular carcinoma was taken into account before surgery. The enhanced pattern, however, led to differential diagnosis of cholangiocarcinoma.
The patient underwent lobectomy and cholecystectomy via laparoscopic surgery. A mass measuring approximately 5 x 4 cm in size, firm, and poorly defined, was found in the posterior portion of the right lower lobe of the liver. The liver was reddish-brown with minor cirrhotic alterations. Postoperative issues, including hemorrhage and biliary fistula, did not occur. He recovered well.
Histopathological and immunohistochemical analyses of the mass showed that the tumor tissue was arranged in nests and sheets along the bile duct; the tumor cells were round or fusiform with pronounced atypia. Immunohistochemical analysis revealed positive staining for cytokeratin, low molecular cytokeratin, and cancer cell wave proteins. Vimentin, cytokeratin (CK)8, and CK-19) were all positive, but CK7, CK10, and hepatocyte paraffin 1 (Hepa-1)were all negative(Figure 3). The Ki-67 proliferation index was approximately 40%. It was determined that the patient had sarcomatoid cholangiocarcinoma based on the findings of histological and immunohistochemical analyses.