ABSTRACT
Tumor markers such as carbohydrate antigen 19-9 (CA19-9) are generally useful in ruling out malignancy of hepatic cysts. The patient was a 72-year-old man who had a ruptured liver cyst in the right liver, which had been noted since he was 67 years old at another hospital. The initial laboratory tests demonstrated elevated CA19-9 (193 784.3 U/mL). We made the diagnosis with a simple ruptured liver cyst from magnetic resonance imaging and cytological examination of ascites, and laparoscopic fenestration with drainage of the abdominal fluid was performed. Pathological diagnosis of the resected wall cyst was non-parasitic simple hepatic cyst with acute inflammation and hemorrhage. The patient's serum levels of CA19-9 were 164.0 U/mL on postoperative day 23. The follow-up abdominal computed tomography scan performed 2 months later did not any finding of tumor.