Elevated CA 125 serum levels and epithelial ovarian cancer metastatic to retroperitoneal lymph nodes

Elevations in CA 125 levels have been reported in approximately 80% of patients with epithelial ovarian cancer. Studies demonstrate that elevations of CA 125 at the time of second-look procedures correlate with the presence of tumor in 100% of cases. Two cases are reported with elevated CA 125 in which clinical examination and noninvasive studies with CAT scans failed to demonstrate tumor. In both cases laparotomy was performed because of the elevation of CA 125. Although intraabdominal exploration did not reveal the source of the CA 125 elevation, extensive retroperitoneal dissection demonstrated microscopic tumor in retrocaval lymph nodes in both cases. The ability to monitor patients with CA 125 is demonstrated and the importance of elevated antigen levels emphasized. Benign conditions associated with falsely positive CA 125 are discussed.