Intrahepatic clear cell cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a cancer of the bile duct in the liver. The clear cell subtype of ICC is a rare cancer; until now, only 8 cases have been reported. The number of reports is so small that a detail description of clear cell ICC is valuable.

A case report will be published on May 28, 2010 in the World Journal of Gastroenterology addresses this question. The diagnostic pathology team led by Associate Professor Dr. Hayashi at the Department of Pathology, Nagasaki University Hospital in Japan collaborated with Professor Nagayasu, Department of the 1st Surgery and Professor Uetani, Department of Radiology, to investigate how the specific "clear cell" change occurs, a patient's underlying disease and choice of chemotherapy, and the prognosis for future patients of this rare cancer.

The patient was a 56-year-old Japanese man with a 3-year histry of hepatitis B virus (HBV) infection. The follow-up echo revealed a tumor of the liver. CT and MRI suggested hepatocellular carcinoma (HCC); a cancer of liver cells. The patient had surgery and the tumor was diagnosed as the rare "clear cell ICC", not a conventional HCC.

Unlike reported cases, this patient had HBV infection as the underlying disease. The cell of conventional ICC is usually small and its nucleus occupies a large part of the cell. Clear cell ICC consists of larger cells with copious cytoplasm possibly caused by mucin, lipid, glycogen or by another unknown reason. Therefore the cells look clear. The cancer cells originating from bile ducts often produce much mucin, however the clear cells in this case did not contain mucin, and had a little glycogen.

The literature review disclosed that the risk of metastasis or recurrence is low after the removal of the cancer. There is not enough evidence for the use of any particular treatment including chemotherapy. Therefore, careful follow-up and the acquisition of more case records are important to obtain more evidence on this cancer.