Abnormally high level of CA-19-9 in a benign ovarian cyst.

CA-19-9 antigen is mainly elevated in cases of gastrointestinal tract malignancy, including of the pancreas, colorectum, and biliary tract. CA 19-9 antigen can also be elevated in ovarian mucinous neoplasms, however, as well as in many benign conditions. Markedly raised levels of more than 10,000 U/mL were almost observed in advanced stage of malignancy. We report herein the case of a 37-year-old woman who presented with an abnormally high level of CA 19-9 antigen associated with benign mucinous cystadenoma.