Unusual Images of Mass-Forming Intrahepatic Cholangiocarcinoma
A 78-year-old Japanese woman, with no particular physical indications like abdominal pain, generalized itching, weight loss, fever or jaundice, who was incidentally found to have changes in liver function tests, particularly an elevated level of alkaline phosphatase (368 U/l), was admitted to our hospital for investigation and treatment. She had no history of HBV or HCV infection or of excessive alcohol intake.\nUltrasonography revealed a solid liver tumor. Computed tomography also showed a large, heterogeneous and hypovascular tumor in the anterior segment; the tumor margin was smooth, clear and demonstrated ring enhancement and low density within the tumor both in early and delayed phase, suggesting degeneration, necrosis or a cystic lesion inside the tumor. Magnetic resonance imaging confirmed the presence of a mass lesion that was isointense on T1-weighted images and minimally hyperintense on T2-weighted images, with slightly lower intense fringe. The tumor was hyperintense on diffusion-weighted imaging. After the injection of intravenous contrast, the T1-weighted image showed peripheral ring enhancement on both early (fig. ) and delayed phases.\nEnhanced magnetic resonance imaging showed that the tumor border was obvious; the tumor was isointense on T1-weighted imaging and showed slightly higher intensity than round on T2-weighted imaging and high intensity on diffusion-weighted imaging (fig. ).\nContrast-enhanced ultrasonography showed a tumor with isoechoic or mixed pattern; a dynamic study showed pycnomorphous tumor margin in the early phase, and the center of the tumor was heterogeneous and hypoechoic in the late phase. Defect re-perfusion imaging showed that the solid part of the tumor was hypervascular (fig. ). 3D volumetric analysis showed that the total liver volume was 1,041 ml (right lobe 660 ml, left lobe 381 ml); the tumor volume was 24 ml (fig. ).\nLaboratory testing showed normal liver enzymes, except for ALP (368 U/l): AST 18 U/l, ALT 15 U/l, total bilirubin 1.0 mg/dl and direct bilirubin 0.1 mg/dl. Complete blood count was normal (WBC 7,100/μl, RBC 4.30 × 106/μl, PLT 343 × 103 and INR 1.0). Tumor markers were all within normal limits, e.g. CEA 4.2 ng/ml, CA19-9 14 U/ml, AFP 3 ng/ml, PIVKA-II 21.0 mAU/ml, etc.\nAlthough the laboratory and radiological findings were not typically pathognomonic for any specific hepatic tumor, the lesion was resected on the basis of a high degree of suspicion for malignancy and submitted for pathologic evaluation. Grossly, a 5.5 × 4.0 × 3.0 cm well-defined and non-encapsulated solid mass was identified (fig. ). Microscopically, the neoplasm was a moderately differentiated adenocarcinoma with abundant fibrous stroma, consistent with a mass-forming CC (fig. ). The patient's postoperative course was generally unremarkable.