2021 Volume 70 Issue 1 Pages 155-159
The patient was a 64-year-old woman. An abdominal ultrasonography performed for screening for upper abdominal discomfort and pain revealed cystic lesions of various sizes up to 4.6 cm throughout liver area S6. The S6 cysts showed clear spontaneous reductions in diameter over time (down to 3.9 cm in September 2016, 3.0 cm in September 2017, and 2.0 cm in October 2019). When similar case reports were searched for in the “Ichushi” medical database, 10 cases were found. In many of these cases, the cause of spontaneous liver cyst reduction was unknown; however, one case was found in which the liver cyst had developed into a cystadenoma as it shrank. Considering the possibility that hepatic cysts that shrink over time may develop into cystadenoma, which may in turn become malignant (cystadenocarcinoma), it is necessary to regularly follow up patients with such cysts.
