Tumor biomarkers: help or mislead in the diagnosis of xanthogranulomatous cholecystitis?--analysis of serum CA 19-9, carcinoembryonic antigen, and CA 12-5

Background Xanthogranulomatous cholecystitis (XGC) is a rare type of gallbladder inflammation. Unlike other cholecystitis, it can be easily misdiagnosed as gallbladder cancer based on radiological images. In response to misdiagnosis, extended surgical treatments are inappropriately given to patients, which is not beneficial to their health and/or recovery. In this study, we set out to determine whether tumor biomarkers can help to avoid misdiagnosis in patients with XGC. Methods Between January 2005 and January 2012, a total of 37 preoperative patients at Sir Run Run Shaw Hospital were suspicious of having gallbladder cancer and was pathologically confirmed to be XGC after surgical operations. Before operations, all patients received a tumor biomarker test to verify diagnosis, which included serum CA 19-9, carcinoembryonic antigen (CEA), and CA 12-5. Results A measured amount (54.05%) of cases (20 in 37) had at least one elevation over the thresholds of CA 19-9 (37 IU/L), CEA (5 ng/ml), and CA 12-5 (35 IU/L), which increased the suspicion of malignancy and consequently enhanced the difficulty to make right diagnosis of XGC as benign. 45.95% of cases (17 in 37) had an elevation in CA 19-9. 2.70% of cases (one in 37) had an elevation in CEA and 24.32% of cases (nine in 37) had an elevation in CA 12-5. Analysis with Fisher's exact test discovered that the presence of common bile duct stone was a contributor to elevations of CA19-9 in patients with XGC. However, even in cases without common bile duct stones, 42.86% of patients (nine in 21) had elevations of at least one tumor biomarker. Among them, 26.09% of patients (six in 21) had elevations of CA 19-9, with the maximum of 536.29 IU/L. Conclusions The elevations of tumor biomarkers in XGC were frequent, suggesting their inabilities to clarify the disease's nature, especially when there was a suspicion of gallbladder cancer. Intraoperative frozen pathology of gallbladder might be a possible solution. However, it is against the en bloc surgical principle and has the potential to cause tumor cell spreading. More research should be conducted, such as the discovery of a novel biomarker, so that XGC can less likely be misdiagnosed as malignancy until the final pathological judgment.