Noninvasive preoperative differential diagnosis of gallbladder carcinoma and xanthogranulomatous cholecystitis: A retrospective cohort study of 240 patients

BACKGROUND: Xanthogranulomatous cholecystitis (XGC) is an extremely rare entity. Due to XGC’s clinical and radiological resemblance to gallbladder carcinoma (GBC), intraoperative frozen section during cholecystectomy is often performed to exclude the diagnosis of GBC. Our study is aiming to find a noninvasive indicator of XGC. To our knowledge, this is the largest XGC cohort ever studied. METHODS: This study retrospectively collected clinical characteristics, serological tests, and imaging features of 150 GBC patients and 90 XGC patients. The diagnosis of these 150 GBC patients and 90 XGC patients was based on intraoperative frozen section histopathology. T‐test was utilized to compare differences between XGC and GBC. Receiver operating characteristic (ROC) curve was conducted and the area under the curve (AUC) was managed to evaluate the validity. RESULTS: The carcinoembryonic antigen (CEA) level in blood tests was significantly elevated in GBC patients than in XGC patients (p = 0.007). The presence of submucosal hypo‐attenuated nodules (80% in XGC, 16% in GBC, p < 0.001), low density border (60% in XGC, 21% in GBC, p = 0.001), and nodular thickening in the bottom of the gallbladder with calcification (70% in XGC, 37% in GBC, p = 0.004) is significantly associated with XGC patients, whereas massive hilar infiltration (0% in XGC, 21% in GBC, p < 0.001), multiple lymph nodes in the hilar area (10% in XGC, 72% in GBC, p = 0.001), and gallbladder mucosal line continuity (50% in XGC, 95% in GBC, p = 0.002) are highly associated with GBC patients. The ROC curve was performed and the gallbladder mucosal line continuity (AUC = 0.708) and the AUC of low density border around the occupation (AUC = 0.654) showed a good prediction of XGC. CONCLUSIONS: Gallbladder mucosal line continuity and low density border around the occupation presented good indication value for the diagnosis of XGC. Our study proposed a noninvasive differential diagnosis method for XGC and GBC.