Temporary spontaneous regression of intrahepatic cholangiocarcinoma.

A 34-yr-old man with a liver mass was referred to the hospital. The mass showed temporary spontaneous regression during the follow-up, however, subsequent regrowth of the tumor prompted surgical resection. The specimen revealed intrahepatic cholangiocarcinoma with two distinct components which had been clearly demonstrated on serial CT. Spontaneous resolution of a lesion does not necessarily suggest the lesion's benign, self-limiting entity. Intrahepatic cholangiocarcinoma should be included in the tumors that could spontaneously regress.