These lesions are watched and not usually treated. The most interesting liver cysts I have personally seen were a series of hydatid cysts caused by the Echinococcus. The Echinococcus is a parasite.

The abdominal CT revealed a 35-mm cyst without calcification in segment IV of the liver (Fig ... characteristic of hydatid cyst. The right bottom corner shows thyroid tissue of the left thyroid ...