Malignant transformation of a 5-mm gallbladder polyp over 2 years: a case report and review of current literature.

Gallbladder polyps (GBPs) are incidentally seen in 4% to 7% of adults on abdominal ultrasounds. Most GBPs are benign cholesterol polyps, adenomyomatosis, or inflammatory polyps. Currently, cholecystectomy is widely accepted as appropriate care for polyps 10 mm or larger as they present a higher risk for malignancy. However, the management of small polyps smaller than 10 mm has continued to be a dilemma to clinicians and radiologists. Many authors support a nonoperative approach with imaging follow-up for polyps smaller than 10 mm, as most have been shown to be benign. However, small polyps do have the potential to be neoplastic adenomas and become malignant. In this report, we will describe a case of a tiny GBP that subsequently developed into a 20-mm carcinoma over a period of 2 years.