Small hepatic S4 cysts refer to small cysts in the left inner lobe of the liver, which are generally relatively small cysts that grow extremely slowly and confined within the liver and are more common in women. They are mostly thought to be congenital, usually due to impaired embryonic development of the intrahepatic bile ducts, or in a small percentage of cases, degenerative changes of the organ or retention lesions. Usually relatively small cysts do not cause changes in the internal tissue structure and external morphology of the liver, and patients do not have any symptoms. In this case, it is only necessary to review ultrasound once every six months or so to observe the changes in the cysts, so there is no need to worry too much; if the cysts grow faster, ultrasound-guided interventional puncture and fluid aspiration and sclerotherapy can be considered.