Xanthogranulomatous cholecystitis: a clinicopathological study of its association with gallbladder carcinoma.

Objectives: To determine the distribution of macrophages (MΦ) in both xanthogranulomatous cholecystitis (XGC) and gallbladder carcinoma (GBC) and to analyze the association between XGC and GBC.

Methods: From January 2009 to June 2011, 110 patients with gallbladder diseases, including 35 with GBC, 45 with XGC and 30 with chronic cholecystitis (CC), were enrolled. Immunohistochemistry stain and real-time polymerase chain reaction using oncogenes (BCL-2, c-Myc) and anti-oncogene genes (p53, p21) were performed, serum expressions of tumor marker (CA19-9, CA724 and CA242) were also conducted. MΦ were used to determine their potential role in the carcinogenesis of GBC.

Results: BCL-2 and c-Myc expressions gradually increased among CC, XGC and GBC (P = 0.032 and P = 0.020, respectively); while p53 and p21 were similar in the three groups (P = 0.167 and P = 0.122, respectively). Serum BCL-2 and c-Myc were significantly correlated with their tissue levels; in terms of serum tumor markers, which gradually increased among CC, XGC and GBC, however, CA242 and CA724 were both negative in XGC but positive in GBC. Furthermore, gradually increasing MΦ counts were observed among CC, XGC and GBC groups; c-Myc and CA724 were independent predictors for the differentiation of XGC and GBC.

Conclusions: XGC is an uncommon inflammatory condition distinct from CC and may be associated with the precancerous nature of GBC for its upregulated oncogenes and MΦ biology. c-Myc and CA724 were independent predictors for the differentiation of XGC and GBC.