Carcinoma in the porcelain gallbladder: a relationship revisited.

BACKGROUND: Gallbladder cancer is the most common biliary tract malignancy. Calcification of the gallbladder wall is reported to be associated with gallbladder cancer. In the literature, the incidence is quoted to be between 12% and 61%. This study aims to clarify the risk of cancer in a calcified gallbladder.

METHODS: The charts and pathology reports at the Massachusetts General Hospital were reviewed, and patients with either gallbladder cancer or a calcified gallbladder were included in the study. The Fisher exact test was used to test for the association between cancer and gallbladder wall calcifications.

RESULTS: From 1962 to 1999, there were approximately 25,900 gallbladder specimens analyzed at the Massachusetts General Hospital. There were 150 patients with gallbladder cancer and 44 patients with calcified gallbladders. Two types of calcified gallbladders were noted: those with complete intramural calcification (n = 17) and those with selective mucosal calcification (n = 27). The incidence of cancer arising in a gallbladder with selective mucosal wall calcification was approximately 7%. There was a significant association between gallbladder cancer and selective mucosal calcification with an odds ratio of 13.89 (P =.01). There were no patients with diffuse intramural calcification and cancer.

CONCLUSIONS: A calcified gallbladder is associated with an increased risk of gallbladder cancer, but at a much lower rate than previously estimated. The incidence of cancer depends on the pattern of calcification; selective mucosal calcification poses a significant risk of cancer whereas diffuse intramural calcification does not.