Polypoid Lesions of Gallbladder: Diagnosis and Follow-Up
Hiromichi Ito*1, Lucy E. Hann2, Michael D'Angelica1, Yuman Fong1, Ronald P. Dematteo1, David S. Klimstra3, Leslie H. Blumgart1, William R. Jarnagin1
1Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY; 2Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY; 3Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY
Background: Polypoid lesions of the gallbladder (PLG) are commonly seen on ultrasonography (US) but optimal management of them is ill-defined. The aims of this study were to assess the natural history and the histological characteristics of US-detected PLG.
Methods: Patients with PLG detected by US from were identified retrospectively. Patients with suspected gallbladder cancer were excluded. Histologic findings were analyzed in patients who underwent cholecystectomy and change in polyp size was determined in patients who underwent serial US imaging.
Results: From 1996 through 2007, 418 patients with PLG detected on abdominal US were identified. Two hundred and thirty patients (55%) were women and the median age was 59 years (range 20-94). Two hundred and sixty-five patients (64%) were found to have PLG on US during the work-up of unrelated disease while 94 patients (23%) had abdominal symptoms. Three hundred and ninety patients (93%) had PLGs ≤1cm while 28 patients (7%) had PLGs >1cm; 59% of patients had a single polyp and 12% had associated gallstones. Among 141 patients who had repeat US followup, growth was observed in 9 patients (7%), no change in 120 patients (85%) and regression in 12 patients (9%). Eighty patients underwent cholecystectomy and the histological diagnoses are shown in the Table. Most patients had no polyps (32%) or pseudopolyps (57%) (including cholesterol, inflammatory or hyperplastic polyps). Adenomas were seen in 9% of patients while invasive or in situ cancer was only seen in 2 patients, both with lesions ≥11mm.
Conclusion: Small PLG (less than 10mm in diameter) detected by US are infrequently associated with symptoms and can be safely observed. The risk of cancer is size dependent, and cholecystectomy is warranted for lesions greater than 10 mm.
Pathological diagnosis of PLG and the size on US
| Histology | Largest diameter of PLG on US | Total (%) | ||
| <1-5mm | 6-10mm | ≥11mm | ||
| Normal gallbladder | 8 | 1 | 0 | 9 (11) |
| cholecystitis (no polyp) | 3 | 3 | 2 | 8 (10) |
| cholelithiasis | 6 | 1 | 2 | 9 (11) |
| Cholesterol polyp, cholesterolosis | 22 | 8 | 3 | 33 (41) |
| Inflammatory polyp | 0 | 0 | 3 | 3 (4) |
| Hyperplastic polyp | 5 | 2 | 3 | 10 (13) |
| Adenoma | 0 | 4 | 3* | 7 (9) |
| Adenocarcinoma | 0 | 0 | 1 | 1 (1) |
| Total | 44 | 19 | 17 | 80 (100) |
*including one adenoma with carcinoma in situ
