Incidentally detected gallbladder polyps: is follow-up necessary?--Long-term clinical and US analysis of 346 patients.

PURPOSE

To determine the natural history of gallbladder (GB) polyps incidentally detected at ultrasonography (US) and to propose management guidelines for these lesions based on polyp size.

MATERIALS AND METHODS

The HIPAA-compliant study was approved by the institutional review board, and informed consent was waived. A database search for "polyp" in all US examinations of the GB between January 1, 1999, and December 31, 2001, at a single institution was performed. All subsequent US reports were reviewed to determine changes in GB polyp size. The electronic medical record was searched to obtain clinical and pathologic follow-up.

RESULTS

Three hundred forty-six patients (mean age, 51.6 years; range, 20-93 years) with GB polyps were included. There were 156 men (45%) and 190 women (55%). US follow-up (mean, 5.4 years; range, 2-11.5 years) was performed in 149 patients (43%). Polyp size was stable in 90 (60%) polyps, decreased in eight (5%), increased in one (1%), and resolved in 50 (34%). Forty-two patients (12%) underwent cholecystectomy, revealing 13 (31%) GBs with polypoid lesions, 24 (57%) with stones and no polyps, and five (12%) with neither a stone nor a polypoid lesion. Clinical follow-up (mean, 8 years; range, 5-10.4 years) was performed in 155 patients (45%). No patient had clinical evidence of GB-related disease. Overall, no cases of GB malignancy were identified in 346 patients. Mean polyp size was 5.0 mm (range, 1-18 mm). No neoplastic polyps were found at 1-6 mm, one neoplastic polyp was seen at 7-9 mm, and two neoplastic polyps were found at 10 mm or larger.

CONCLUSION

The risk of GB malignancy resulting from incidentally detected polyps is extremely low. Incidentally detected GB polyps measuring 6 mm or less may require no additional follow-up. Data are inconclusive regarding polyps 7 mm or greater, and further studies are warranted.