Gallbladder Polyps Rarely Grow Beyond 10mm - Close Surveillance is Unnecessary for Polyps Smaller than 10mm

Abstract

Introduction: Small gallbladder polyps (GBP) are usually asymptomatic and benign and are monitored with regular ultrasonography (US) surveillance. Although most centers repeat imaging within a year, there remains no consensus regarding appropriate scan intervals.Aims: To investigate the size stability of GBP and to review the need for close surveillance.Methods: All abdominal ultrasound scans performed in our hospital over 3-month period were reviewed. Patients with sonographic evidence of GBP and with subsequent surveillance were included. The demographics of patients, characteristics of polyps, and subsequent scans over the following five years were reviewed. Histological reports were obtained for patients who underwent cholecystectomy.Results: 96 patients were included in the study. Median age was 51 (range, 24-89) years with a male predominance (67.7%). Main indications for US were hepatitis follow-up (41.7%) and abdominal pain (20.8%). Most patients had multiple polyps (62.5%) and the median diameter of the largest polyp was 4 (range, 3-10) mm. An average of 4.5 scans were performed over five years following detection and most polyps remained stable in size, rarely growing beyond 10mm -only two patients had polyps beyond 10mm. No gallbladder carcinoma was detected during the follow-up period. Conclusion:GBP usually remain stable in size, seldom grow beyond 10mm, and are rarely malignant. Surveillance scans for polyps smaller than 10mm should not be performed at intervals less than a year.

The growth rates of solitary gallbladder polyps compared to multi‐polyps: A quantitative analysis

“…Our study adopted the ESGAR guidelines recommendation of ≥2 mm increase in GBP diameter as an indicator for 'true' GBP growth between two ultrasound examinations, 1 which found that only 8/100 (8%) of GBPs grew ≥ 2 mm in size over a mean follow-up period of 17.9 [AE 9.5] months. Similar findings where >85% of GBPs grew minimally at follow-up have been reported in one systematic review and two studies 6,26,27 : a systematic review found 5673/6100 (93%) of GBPs exhibited no growth or remained stable after a mean follow-up period of 51.5 (1-184) months. 6 A prospective study performed at the S. Orsola-Malpighi hospital in Italy found that 48/53 (91%) of GBPs did not change in size after a 5-year follow-up.…”

“…Firstly, it is likely that most GBPs detected in both study groups were cholesterol polyps, given that up to 80% of GBPs are typically cholesterol in origin. 1,6,7,26 Secondly, a systematic review found solitary GBPs had an increased malignancy risk by a factor of only 2.05 (P < 0.001) compared to multi-polyps, 1,6 while other studies have not found an associated significance on multivariate analysis. 1,9 As a result, the ESGAR guidelines stated there are no strong data to support a definitive association between solitary GBPs and malignancy risk.…”

“…1,9 As a result, the ESGAR guidelines stated there are no strong data to support a definitive association between solitary GBPs and malignancy risk. 1 Since there is some evidence to suggest that rapid growth rates are associated with increased malignancy risk, 18 and with the rarity of gallbladder carcinoma, 1,4,6,26 it is plausible that most GBPs sampled in both study groups were benign and therefore exhibited minimal growth. 1,4,18 Since solitary GBPs have not been shown to date to grow at a higher rate compared to multi-polyps, no additional follow-up imaging is required to monitor solitary GBPs compared to multi-polyps.…”

“…1 Furthermore, recommendations concerning follow-up time intervals for GBPs <10 mm in size vary in the literature. 1,4,6,7,26 The ESGAR guidelines acknowledge that there is only low-quality evidence for GBPs <10 mm in size in regard to appropriate time interval between ultrasound examinations and duration of follow-up. 1 This is due to the lack of high-quality studies and the challenges in determining which GBPs <10 mm in size are malignant.…”

“…The aims of this study were to analyse GBP growth over a period of up to four years to ascertain whether there is a statistically significant difference in growth rates between solitary GBPs and multi-polyps, and to determine the proportion of GBPs that exhibited growth in this study's cohort compared to previous studies reported in the literature. 6,26,27 If solitary GBPs are found to possess faster growth rates than multipolyps, additional monitoring for solitary GBPs may be required, as there is increased potential for solitary GBPs to reach ≥10 mm in size, where malignancy risk is greatest. 1,2,3,4,6,10,12 Materials and methods A quantitative, retrospective, cohort study was performed utilising patient records from three private radiology clinics in Sydney.…”