Abstract
A 63-year-old Japanese man was referred to our medical center for further examination of a hepatic tumor. Computed tomography (CT) and magnetic resonance imaging showed a strongly ring-like enhanced tumor with a diameter of 65 mm in segment VIII of the liver. There were no other intraabdominal or intrapleural lesions. Since it was diagnosed as intrahepatic cholangiocarcinoma (ICC) or combined type hepatocellular carcinoma, a right hepatic lobectomy was performed. Macroscopically, the excised specimen was a white, non-capsulated tumor which was growing expansively. Histopathological findings showed that the tumor cells had large clear cytoplasm, proliferated in a glandular pattern and formed an irregularly fused solid nest. Periodic acid Schiff (PAS) staining suggested that the cause of the clear cytoplasm was glycogen. Immunohistochemical stainings of CD10, Vimentin, alpha fetoprotein, HepPar1, CK7 and CK20 were all negative. These pathological findings confirmed that the diagnosis of intrahepatic clear cell cholangiocarcinoma (ICCC). ICCC is an extremely rare ICC variant where only nine cases have been previously reported. According to these reports, it is considered that the prognosis of ICCC may not be as poor as that of ICC. The present patient is alive and free from recurrence for 15 months after the surgical operation.
