|Year : 2022 | Volume
| Issue : 2 | Page : 130-133
Gallbladder polyps: Is a cancer phobia justified?
Aaditya Bhatwal1, Akshay Bavikatte2, Puneet Dhar1
1 Department of Surgical Gastroenterology, Amrita Institute of Medical Sciences, Kochi, Kerala, India
2 Department of General Surgery, Amrita Institute of Medical Sciences, Kochi, Kerala, India
|Date of Submission||11-Oct-2021|
|Date of Decision||16-Mar-2022|
|Date of Acceptance||22-Mar-2022|
|Date of Web Publication||29-Aug-2022|
Dr. Aaditya Bhatwal
Bhatwal Surgical & Maternity Hospital, 111/A, Agrawal Nagar, Dhule - 424 001, Maharashtra
Source of Support: None, Conflict of Interest: None
Background: With better imaging technologies, the frequency of detecting GB polyps has increased, however, their effective management remains a clinical dilemma. Aims: This study was aimed to assess the true outcome of lesions suspected or diagnosed as gallbladder (GB) 'polyp' on ultrasound. Patients and Methods: Computerised hospital-based medical records between June 2008 and June 2014 at a medical sciences institute in Kerala were accessed to identify and review the follow-up of all cases identified as GB polyp on ultrasound. Results: Ultrasound examination was performed in 108 cases. Of these 46% had symptoms suggestive of gall bladder disease, 20% had nonspecific abdominal symptoms and for the remaining 34% it was part of routine health check-up. The mean polyp size was 4.7 mm. During follow-up, 20 (18.5%) patients underwent cholecystectomy and none of them came as true polyps on histopathology, 25 (23%) patients were lost to follow-up after primary ultrasonography and 10 (9.25%) patients died due to reasons unrelated to GB disease. Conclusion: Radiologists tend to over diagnose GB polyps due to the risk of malignant transformation of GB polyps and increased usage of imaging modalities. It is observed in this study that higher imaging modalities do not add significant specificity in the diagnosis of the true polyp. However, there is a need for a large cohort study to confirm the outcome.
Keywords: Gallbladder, neoplastic changes, polyps, ultrasound examination
|How to cite this article:|
Bhatwal A, Bavikatte A, Dhar P. Gallbladder polyps: Is a cancer phobia justified?. J Med Evid 2022;3:130-3
| Introduction|| |
Gallbladder (GB) polyps are elevated mucosal lesions of the gallbladder wall that project into the lumen and can be divided into pseudopolyps and true polyps. Many other pathological lesions can give a similar appearance on commonly used imaging modalities, resulting in more pseudopolyps being identified than true polyps. The majority of GB polyps are benign, and when removed by cholecystectomy, the typical finding is that they consist of cholesterol and inflammatory polyps, soft calculus embedded within the GB mucosal folds/rugae, but the malignant transformation is a concern.
GB polyps are reported in about 5% of the healthy population who undergo abdominal ultrasonography (USG)., In most of the cases, it is an incidental finding without any associated abdominal clinical symptom. Standard ultrasound features of GB polyps are protrusion of internal GB wall of similar echogenicity as that of the GB wall and hyperechoic compared with the surrounding bile, lack of mobility and no associated posterior acoustic shadow. This diagnosis is a potential source of worry for the patient as it immediately confers a 5% possibility of malignant change and forces many to even consider surgery. However, pre-malignant GB polyps have characteristics such as size >10 mm, single rather than multiple, rapid change in size on follow-up USG and adenomatous nature. With the increased use and quality of imaging technologies, the frequency of detecting GB polyps has also increased, however, their effective management remains a clinical dilemma.
This study was undertaken to assess the true outcome of lesions suspected or diagnosed as GB 'polyp' on USG.
| Materials and Methods|| |
This retrospective study was conducted at Amrita Institute of Medical Sciences, Kochi, Kerala. A database was used to search for GB polyp in all abdominal USG examinations performed between June 2008 and June 2014.
Detailed patient information including demographics, medical history and clinical and pathological reports were obtained from the computerised hospital-based medical records. Follow-up visit information with change in polyp size and surgery performed if any were also recorded. Attempts were made to obtain follow-up information telephonically when subsequent records after initial contact and USG were not available. All USG reports were interpreted by experienced radiologists.
Data were recorded into an electronic database and quality checked for accuracy. SPSS version 20 ( IBM Inc.Armonk, New York, NY10504, USA) was used for the statistical analysis. Descriptive methods including averages and graphs were used to represent data.
| Results|| |
A total of 108 patients with GB polyps were identified in the study which included 87 (81%) males and 21 (19%) females. The mean age of the study population was 50.4 (±13.3) years with a range of 21–80 years, as shown in [Table 1]. Forty-six per cent of study patients had symptoms related to GB disease which indicated USG, while 20% of patients were having symptoms not related to GB diseases. The remaining 34% of patients had USG as a general health check-up [Figure 1]. Seventy-one (65.7%) patients had multiple polyps, while 37 (34.3%) patients had a single polyp. The mean polyp size of the study population was 4.7 (±2.15) mm with a range of 1–15 mm, as described in [Table 2]. Based on criteria of evaluation, patients considered for surgery had size of GB polyps more than 10 mm. Patients with polyp size between 5 mm and 10 mm had to be symptomatic the rest being on follow-up. Patients with polyp size <1 mm were not considered for follow-up. On this basis, 15 cases were chosen for surgery, 13 symptomatic and 2 with polyp size more than 10mm. However, 4 more cases were operated since they were apprehensive about GB polyp being a precancerous condition, and one who thought getting operated was a better option than visiting again and again for observation and follow up. Hence 20 patients underwent surgery [Table 3].
USG follow-up was performed in 53 (49%) patients with a mean follow-up duration of 24 months (range: 1–5 years). Twenty (18.5%) patients underwent cholecystectomy for GB polyps, 25 (23%) patients were lost to follow-up after primary USG and 10 (9.25%) patients died due to reasons unrelated to GB disease [Figure 2]. Causes of death unrelated to GB polyps were natural death due to old age, complications due to uncontrolled diabetes and advanced carcinoma of sigmoid colon. Amongst patients with regular follow-up, polyp size was stable in 23 (43.3%) patients, while it decreased in 8 (15%) and increased in 5 (9.4%) patients. Polyps resolved in 17 patients during routine follow-up [Figure 3]. Amongst 20 patients who underwent cholecystectomy, 12 (60%) had stones and 8 had polyps, as mentioned in [Table 3]. None of these eight polyps were adenomatous and showed any neoplastic change on histopathology.
Most of the GB polyps were incidentally detected when USG was performed. Additional imaging modalities were done to ascertain malignancy and to rule out other abdominal complaints such as mass in the colon, biliary stricture and pancreatitis. Only two cases underwent additional scan due to the GB polyp's size of equal to more than 10 mm. Amongst all study patients, 16 had additional imaging which included computed tomography (CT) scan (14 patients), magnetic resonance imaging (MRI) (1 patient) and EUS (1 patient), of which 10 patients were operated on. Amongst these 10 operated patients, 9 had CT scans performed and radiologists reported definitive diagnosis of polyp in only 2 patients, who had cholesterol polyps on histopathology. Overall, no GB malignancy was identified in any of 108 study patients till the end of the study.
| Discussion|| |
As the use of USG is increasing, even during general health check-ups, the incidental detection of GB polyps is on the rise. Due to the potential for malignancy even though rare, any incidental GB polyp cannot be ignored., However, it is important to establish follow-up guidelines based on polyp size and other related parameters including clinical symptoms.
This study was conducted to assess the true outcome of GB polyps identified on USG. A higher proportion of male patients were observed in the study compared to female patients, which is in contrast to reported in similar studies conducted outside India., This may be attributed to more frequent health check-ups by males compared to females in India. The mean polyp size of 4.7 mm observed in the study is in line with the reported average 5-mm polyp size by Pedersen et al. and Corwin et al. in two different studies.
In this study, most of the patients were regularly followed up and polyp outcomes were reported. The majority of the GB polyps were stable on size or resolved. Only two patients had polyp size >10 mm and none of the patients had malignancy till the end of the study. These study results indicate that GB polyps measuring <10 mm may not require additional follow-up and the decision to operate should also consider patient symptoms rather than only the size of the polyp. Kim et al. reported that polyp size ≥15 mm on USG is the strongest predictor for neoplasia. Hyperechoic foci in a polyp on USG and its CT visibility can be useful indicators for the differentiation of a neoplastic polyp, along with other established predictors. Several other studies have indicated that malignancy is very rare in GB polyp of <10 mm size, however, patients should be observed for change in polyp size.,,,, Babu et al. have suggested the management of GB polyp based on size which includes no follow-up for <5 mm, 6 monthly scans for 5–10 mm and cholecystectomy for >10 mm polyp size, which is in line with reported by Wiles et al. and Elmasry et al.,,
The decision to operate or not based on USG is a dilemma for GB polyps of <10 mm. In this study, 12 (60%) of 20 operated patients were having a stone which was misdiagnosed as a polyp on USG. Immobility due to GB contraction and/or absence of post-acoustic shadow in USG may attribute to the misdiagnosis of GB stone as GB polyp. The patient needs to be adequately fasting before USG for accurate diagnosis of GB polyps, however, it is often missed due to acute abdominal symptoms or need of USG as a walk-in procedure. The remaining eight operated patients had non-adenomatous polyps, which again reveals limitations of imaging modalities to differentiate true polyps from pseudopolyps. Many other investigators had observed a similarly large proportion of misdiagnosis of GB polyp in different studies which were revealed after surgery.,,, Zielinski et al. compared surgically resected polypoid lesions of the gallbladder to their pre-operative ultrasound characteristics and found that even modern ultrasound techniques are unable to accurately differentiate GB polyps.
GB polyp on USG may raise apprehension in patients which may result in cholecystectomy which was also observed in this study. Uncertain treatment modalities and even minimal potential risk of malignancy may result in overdiagnosis of GB polyps, repeated follow-up and costly imaging procedures which may lead to an unwanted burden on healthcare. Higher imaging modalities such as CT, MRI and EUS had not provided any additional information confirming polyps in this study, which is in contrast to the observations by Kim et al. Several attempts have been made to understand and predict malignancy potential from imaging results, however, firm results and guidelines are still lacking. We suggest having a large-scale prospective assessment of neoplastic predictors and management guidelines for GB polyps.
The retrospective observational study design was the limitation of the study which could lead to selection bias. Moreover, the sample size of the study was relatively small considering the low prevalence of outcomes. Amongst study patients, the proportion of patients with polyp size <10 mm was very low, and the neoplastic outcome was not observed which limits the generalisation of the results.
| Conclusion|| |
Increasing use of ultrasound results in overdiagnosis of GB polyps. Many of these GB polyps do not progress, some of these have size reduction and a few disappear. Those patients who show an increase in polyp size should be managed more on clinical rather than radiological evidence. Cross-sectional imaging modalities do not add significant specificity in the diagnosis of true polyp, ultrasound still holds the fort. The risk of GB malignancy resulting from incidentally detected polyps is extremely low, and incidentally detected GB polyps measuring <10 mm may require no additional follow-up.
The authors would like to thank all the faculties and colleagues of the Department of Surgical Gastroenterology at Amrita Institute Medical Sciences, Kochi.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3]