Heavy black tea consumption and elevated CA 19-9 and CA 125 levels. A case report on a patient with ovarian endometriotic cysts.

In this case report, we present a case of false positive CA 19-9 and CA 125 levels in a patient with suspected endometriotic cysts. The patient is a 34-year-old nulliparous woman with heavy black tea consumption and elevated CA 19-9 and CA 125 levels. After discontinuation of black tea intake and careful exploration of other possible factors, CA 19-9 and CA 125 levels dropped markedly. As a conclusion, heavy black tea consumption can lead to false positive results of elevated CA 19-9 and CA 125 levels.