Xanthogranulomatous cholecystitis: the use of preoperative CT findings to differentiate it from gallbladder carcinoma

A retrospective analysis was performed on 32 patients with histologically confirmed xanthogranulomatous cholecystitis (XGC) and 21 patients with gallbladder carcinoma who underwent surgical treatment between 1998 and 2007. All patients underwent preoperative CT scanning. The CT features analyzed were: the presence of intramural hypoattenuated nodules or bands, mucosal line, the patterns of wall thickening and enhancement, and the presence of stones in the gallbladder. The variables of the CT findings with XGC were analyzed using multivariate logistic regression analysis. Intramural hypoattenuated nodules were observed in 21 patients (65%) with XGC, but in only six patients (29%) with gallbladder carcinoma (P < 0.01). The mucosal line was observed in 27 patients (84%) with XGC and in only four patients (19%) with gallbladder carcinoma (P < 0.0001). Gallstones were noted in 24 patients (75%) with XGC and five patients (24%) with gallbladder carcinoma (P < 0.001). There was no significant difference in the pattern of gallbladder wall thickening (diffuse or focal) and the presence of changes outside the gallbladder. Multivariate logistic regression analysis revealed from the CT features that the enhanced continuous mucosal line (P = 0.0013) and the presence of gallstones (P = 0.0072) were independently correlated with XGC. CT features of the enhanced continuous mucosal line in a thickened gallbladder wall, together with gallstones in a patient with chronic gallbladder disease, are highly suggestive of XGC. Accurate diagnosis of XGC may therefore indicate the need to select a less aggressive surgical approach.