PROFILE OF COLONIC POLYPS IN A TERTIARY CARE CENTRE IN SOUTH INDIA.

Aim : To study the prevalence,histopathological types and pattern of distribution of colonic polyps in a cohort of patients evaluated in our tertiary care centre. Materials and Methods : Data of patients undergoing colonoscopy between 2017-2018 for various abdominal complaints were analysed retrospectively for presence of colonic polyps.Age , gender, clinical symptoms and histopathological analysis were also included in the study.Statistical analysis was done using SPSS 23.0 version to arrive at correlations between pattern of distribution and histopathological types. Results : A total of 1423 Colonoscopies were done during the 2 year period. Of them 152 cases were found to have Polyps including few patients with multiple polyps and overall a total of 207 Polyps were studied.Mean age

1239 rectal bleed , abdominal pain , intestinal obstruction and rarely malignant transformation.Hence colonoscopic surveillance and polypectomies are advocated to reduce the incidence of colonic malignancies.
In this observational study we sought to find the prevalence rate of colonic polyps.The study also analysed the pattern of distribution of polyps and various histopathological types.

Materials and Methods:-
Data of patients undergoing colonoscopy in our department over 2 years period between July 2016 to June 2018 were analysed retrospectively for presence of colonic polyps.For each patient,demographical profile including age,gender & indication for colonoscopy was noted.Data regarding the location of the polyp,number of polyp and morphological details including presence and absence of stalk and histology of the polyps were recorded.Details regarding the presence and severity of dysplasia in polyps were also noted.

Statistical Analysis :
The collected data were analysed with IBM.SPSS statistics software 23.0 Version.To describe about the data descriptive statistics frequency analysis, percentage analysis were used for categorical variables and the mean & S.D were used for continuous variables.To find the significance in categorical data Chi-Square test was used.

Results:-
A total of 1423 colonoscopies were done during the 2 year period.Of them 152 cases were found to have polyps.A total of 101 patients had single polyp while others had multiple.Overall a total of 207 polyps were studied that were detected in these 152 cases.
Mean age of the cases was found to be 57.61 years.Polyps were found to be more common in males as 118 out of 152 (77.6 %) were males while 34 out of 152 (22.4%) were females.
Colonoscopic examination showed that polyps were distributed throughout the length of the colon,however as shown in table 1 they were found to be more commonly localized on the left side as 52 polyps (25.1 %) were located in sigmoid and 42 polyps (20.3%) were found in rectum while in cecum only 17 polyps (8.2 %) were seen.Morphologically Sessile polyps were more commonly seen as 160 polyps (77.3%) were sessile and only 47 polyps (22.7) had an stalk and were pedunculated.
Histopathological evaluation of the polyps showed that most of the polyps were either adenomatous (63.7%) or Hyperplastic (28%).Other less common varieties as shown in table 2 were serrated polyps (6.3%) and very few cases having juvenile retention,peutz jehgers and lymphoid polyp.
Among patients having adenomatous polyp (n =132),Tubular adenoma was the commoner subtype as 109 polyps (82.5 %) were tubular and remaining 23 (17.5%) were tubulovillous and none of the polyps had pure villous histology. High grade dysplasia was more commonly seen in patients having tubulovillous adenoma as 7 out of 23 (30.4%) polyps had high grade dysplasia while amongst patients with pure tubular pattern only 2 out 109 (1.8%) patients had high grade dysplasia.
Similarly In relation to the size of the polyp,Larger size adenomas were more commonly associated with high grade dysplasia as 4 out of 9 (44.4 %) adenomatous polyps with size > 2 cm were associated with high grade dysplasia while only 3 out of 96 (3.1 %) adenomatous polyps of size < 1 cm had high grade dysplasia.
Amongst 58 Hyperplastic polyps most of them were small and < 1 cm in size (84.4 %) and none of them showed any degree of dysplasia.Serrated polyps was the third most common variety seen in this study,Out of 13 serrated polyps 8 were pure serrated and other were mixed polyps with 3 being tubularserrated and other 2 were hyperplasticserrated.High grade dysplasia was seen in 2 out 8 (25 %) pure serrated and 1 out 3 (33.3) tubular serrated polyps.

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In regard to Indication of colonoscopy in our institution as shown in table 3, chronic diarrhea (27.6 %),constipation (23.7%) and bleeding per rectum (21.1%) were the most common indication for cololonoscopy in these patients.

Discussion:-
Colonic polyps is not an uncommon finding in colonoscopic studies and with few of them carrying the risk of being precursor of malignancy it is important to characterize them as neoplastic and non neoplastic polyps.Prevalence of colorectal carcinoma are widely available and show that it is much commoner even in Asian population although less frequent compared to western population 6,7 . In India , the crude rate is 2 per 100,000 6,7 while it is approximately 4 per 100,000 in Sri Lanka 8 and 3 per 100,000 in Thailand 6,7 .Present study showed that around 10.6 % of patients undergoing colonoscopy in this tertiary centre in southern India had colonic polyps.This is similar to a study done by Jain M et al 4 who found colonic polyps amongst 12.7 % of all cases undergoing colonoscopy,however another study from Kerala by Tony J et al 3 noted polyps only in 5.1% of completed colonoscopy studies.Thus suggesting that chances of polyp detection rate is higher in symptomatic patients then in patients who are asymptomatic.In this study median age of the cases was 57.6 years which is slightly lower then in a study done by Jain M et al 4 in which median age was 61.1 years.However other studies including a study by Kumar et al 9 and an Amarapurkar series 10 showed polyp detection in relatively more younger patients.
In the present study most of the polyps were adenomatous (63.7 %) while next most common histological type was hyperplastic (28 %). Other South Indian studies also showed similar results as in study done by Jain M et al 4 in Tamil Nadu ,most common polyp type was adenomatous (48.9 %) followed by hyperplastic (23.7%) and similarly another study done in Kerela by Tony J et al 3 had still higher number of adenomatous polyps (79.8%) and they also 1241 showed that amongst adenomatous polyps subtypes tubular was most common variety,followed by tubulovillous (24%) which is in concordance with the present study. However Wickramasinghe et al 11 found tubulovillous polyps were the commonest thus suggesting that polyp profile may vary differs in different regions owing to ethnicity,variations in pathology reporting and other environmental factors.
In regards to associated dysplasia in polyps , Tony J et al 3 showed that severe dysplasia was found in 43% of polyps with villous pattern and 12% of those with tubular pattern however in this study only 1. Similary this study also showed that serrated polyps also tends to have higher malignant potential and more chance of having high grade dysplasia thus these polyp should preferably always be removed.
Hyperplastic polyps in our study were mostly smaller in size < 1cm and distally located and did not had any evidence of dyplasia,Thus whether During Colonoscopy to remove and sent for histopathological analysis of diminutive, distally located polyps is still a matter of debate as chances of most of them being non adenomatous is high.Few Institutions also follow Remove and Discard policy for smaller polyps to prevent any unnecessary risk of harbouring an adenoma by the patient.With the advent of newer advanced imaging endoscopic techiniques in the form Dye based Chromoendoscopy 13 and Electronic Chromoendoscopy like Narrow Band Imaging 14 , colonic polyps can be better characterized and be differentiated into being neoplastic or non neoplastic,however long term studies are required to ascertain there role in this important differentiation and thus helping in prevention of colorectal cancer until then histopathological analysis of the of polyps remains the mainstay of polyp characterization of polyp morphology.

Conclusion:-
Colonic polyps were found in around 10 % of all colonoscopies & seems to be less common in south Indian population than in the West. However Similar to west adenomatous polyps are the predominant histologic type found here and amongst them larger polyps & polyps with villous component are more commonly associated with high grade dysplasia then smaller & tubular polyps.Most of the polyps are located in the left colon and are sessile.Hyperplastic Polyps were found to be completely non neoplastic without any degree of dysplasia.In contrast Serrated polyps are often associated with high grade dysplasia thus all serrated polyps should be removed.