Gallbladder adenomyomatosis: experience at a community teaching hospital

Abstract

Objective: Gallbladder adenomyomatosis (GBAM) occurs in 2-9% of cholecystectomies and is a common mimicker of gallbladder cancer (GBCa). We sought to characterize our experience with GBAM to better recognize the characteristics of GBAM patients. Interestingly, although several recent reports focused on distinguishing presumably benign GBAM from cancer by imaging, several older case reports and series suggest GBAM progresses to GBCa. Methods: A retrospective chart review of 6,877 patients who underwent cholecystectomy (2001–2013) was performed. Statistics included two-tailed t-tests, χ2 tests, and logistic regression analysis. Cases were re-reviewed by a pathologist. Results: Among the 6,877 CCYs, 31 (0.45%) were found to have GBAM. Those with GBAM had were older (66 vs. 52 years, P < 0.001), with similar sex distribution. GBAM patients also had higher ASA scores (P = 0.007). Gallbladder sludge was more common in GBAM cases than noncases (20% vs. 5.6%, P = 0.032), as were gallbladder polyps (10% vs. 1.4%, P = 0.001), but these were predominantly cholesterol polyps. GBAM was not associated with cancer; rather, the most parsimonious fit of the logistic regression showed that age was the strongest predictor of GBCa (OR 1.07, 95% CI=1.051.10). Conclusion: While other studies have shown an association between GBAM and GBCa, analysis of our very large cholecystectomy database did not, but given our surprisingly low incidence of GBAM, there was insufficient power to detect an association if it did exist. GBAM may not be as common as previously thought. The establishment of registries may be a useful way to study GBAM in the future.