Serum and cystic fluid CA 19-9 determinations as a diagnostic help in liver cysts of uncertain nature.

The distinction between hepatobiliary cystadenoma or cystadenocarcinoma and simple hepatic cyst complicated by intracystic hemorrhage may prove difficult to determine on the sole basis of clinical and radiological features because of the presence of intracystic structures and septations well-demonstrated by ultrasound examination in both situations. We investigated four patients with various types of hepatic cysts, in whom diagnostic difficulties led to further investigations. In this small group, CA 19-9 serum levels were abnormal only in the two patients with cystadenoma or cystadenocarcinoma. Cystic fluid CA 19-9 values were also five times higher in cystadenoma and cystadenocarcinoma than in other benign lesions. Our data thus suggest that the determination of serum and cyst fluid CA 19-9 may be of help in distinguishing between hemorrhagic simple cyst and cystadenoma or cystadenocarcinoma.