Study of clinico-pathological characteristics of colonic polyp seen at a tertiary care hospital in East India

Introduction

Colonic Polyp are unusual growths of epithelial tissue projecting from the mucosa of the large bowel. They may be classified according to their gross appearance (sessile or pedunculated), histopathological features (hyperplastic, adenoma, etc.), and behavior (benign or malignant). The biggest concern is their ability to progress into adenocarcinoma, through the adenoma to carcinoma sequence due to genetic mutation.1, 2, 3 The prevalence of colonic polyps in western population parallels the colorectal carcinoma rate and varies between 6.8% to as high as 22%. Prevalence rate in India also differs among regions with a range of 5.1% - 12%.4, 5

With the use of Colonoscopy as an outpatient procedure to see inside of the colon and rectum and used in screening, diagnostic and therapeutic of rectal and colon diseases.6 Most of the colorectal carcinoma (80-90%) originates in association with polyp which progress to dysplasia and if untreated progress to adenocarcinoma in situ and invasive adenocarcinoma.7 Early recognition of these polyps and colonoscopic polypectomy following histopathological examination are important for identifying the neoplastic type of the lesion for further patient management. This study aimed to evaluate the frequency of histological pattern of polyp among colorectal polypectomy specimen concerning age, sex, size, and site and with special emphasis on type of polyp and associated dysplasia.

Material and Methods

The study was done in the Pathology department in collaboration with the Gastroenterology Department on 115 patients in one year time who were send for colonoscopy as per their clinical presentation. All data regarding demographical profile including age, gender & indication for colonoscopy was noted. Colonoscopies were done on these patients and if polyp seen were excised and sent to pathology department in 10% neutral buffer formalin container. A total of 115 polyps were send for histopathological study. All the biopsy specimen was put in 10% neutral buffer formalin for 24 hours for fixation.

The biopsies were grossly examined with emphasis on size, external surface, and cut surface. These findings were recorded and the representative bits were given. The tissue was processed and was cut into five-micron sections. Slides were stained with Haematoxylin-Eosin stain. The colonoscopic findings were obtained from the patient’s record file and histopathological forms. The histopathological features were studied by Pathologist and types the polyps were reported based on histology and presence or absence of dysplasia.

Patient data were entered in Microsoft Excel and descriptive data analysis was done. 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 of dysplasia were also noted.

Result

The present study was done on 115 colonic biopsy were received by Department of Pathology from the gastroenterology Department. Most of the patient had come to Gastro department having clinical presentation like constipation (40.87%) followed by rectal bleeding (40.00%) followed by pain abdomen and anemia. The majority of biopsies were of male patients 76(66.08%) followed by 39 (33.91%) female patients. Among male patients most were in age range of 50-59yr (18.42 %) and in females most of the patients were of age range of 60-69yr. (25.64%)

Colonoscopic examinations were done for these patients and following gross features were noted like polyp appearance, size and site of the lesions are noted. Most polyp are of pedunculated shape (74.78%) followed by ulcerated type (13.04%) and least was of sessile appearance (12.17%). In respect to site of the lesion , most of the polyp were found in left side (descending colon: 40.87%) followed by rectum (24.35%) then by ascending colon (13.91%) and sigmoid colon(8.70%) and transverse colon (6.96%) and lastly by caecum (5.22%). Regarding the size of polyp most of the Polyps size were less than 1 cm (90.40%) followed by size of polyp by more than 1 cm (9.60%).

Regarding the histopathological evaluation of polyp we have reported tubular adenoma (53.91%) followed by hyperplastic polyp (19.13%) followed by tubulovillous adenoma (13.04%). The lesser commoner were Juvenile polyp (11.30%) and retention polyp (2.61%).

Most of the polyp showed no dysplasia (94.64%). The dysplasia were seen more in adenomatous polyp showing high grade dysplasia in form of nuclear stratification and broadening of nuclei with equal proportion both in tubular adenoma and tubulovillous adenoma.

Figure 1

Showing an adenomatous polyp with tubular architecture (H&E Stain 100X).

Figure 2

Showing tubular configuration of gland with nuclear palisading and stratification with apicalmucin (H&E Stain 400X).

Discussion

Among carcinoma in the western population, colorectal carcinoma stands fourth in the list. In India, the incidence of colorectal carcinoma is on rise, and importance of prevention and screening strategies should be focused. Colonoscopy has become most effective screening modalities because recognition and endoscopic removal of the colorectal polyp using colonoscopy can reduce the incidence of colorectal cancer by up to 90 percentage.8

In our study we had majority of male patient with age group of 50-59 yrs age group. This is in par with study by Rahul et al showed median age of the cases was 57.6 years which is slightly lower than in a study done by Jain M et al in which median age was 61.1 years.9 However other studies include studies by Kumar et al and an Amarapurkar et al showed polyp detection in mostly younger patients. 10, 11

The majority of biopsies were of male patients 76 (66.08%) followed by 39 (33.91%) female patients. Male predominance was observed similar to Tony et al, Yousuf et al and Lee et al.12, 13, 14 Even studies conducted by Albasri A et al and Al Rashed et al from Saudi and Kuwait showed male predominance.15, 16 but Nouraie M et al showed female predominance in their study.17

In our study most of the patient had come with clinical presentation like constipation (40.87%) followed by rectal bleeding (40.00%) followed by pain abdomen and anemia. Lorn et al study showed diarrhoea and abdominal pain as the most important causes for colonoscopy. 18 In study conducted by Bafandeh Y et al showed blood in stool, change in bowel habits, and abdominal pain as most important causes for colonoscopy. Seo et al and Cheon et al both reported rectal bleeding followed by abdominal pain and diarrhoea in their study for colonoscopy.19, 20

Among gross features we have encountered 74.8 percentage of polyp in colonoscopy which appeared pedunculated type of polyp followed by ulcerated type (13.04%) and least were of sessile nature (12.17%). Rahul et al study showed morphologically sessile polyps were more commonly seen (77.3%) and around (22.7%) only had a stalk and were pedunculated.21 But Jain M et al showed only 45% of the polyps was pedunculated. 9 Our study showed concordance with Dipika et al study which showed Out of 168 polyps, 118 polyps were pedunculated and 50 were sessile.22

In our study most of the polyp were in descending colon (40.87%) followed by rectum (24.35%) then by ascending colon (13.91%) and sigmoid colon (8.70%) and transverse colon (6.96%) and lastly by caecum (5.22%). Albasri A et al found 36.6% of polyps in sigmoid colon, followed by 21% in rectum. In other study rectum (49.7%) was the second most commonest site followed by a sigmoid colon (15.6%) which is in concordance with the studies done by Tony et al, Wickramasinghe et al and Kumar et al.21, 22, 10 But most of the studies showed Rectum followed by sigmoid as most common site for polyp formation.

With regard to size of polyp 90.40 percentage of polyp size less than 1 cm followed by 9.60 percentage of polyp of more than 1 cm.23 Similar study findings by Rahul et al showed that most polyps (75.8 %) were smaller in size < 1 cm, while only 6.3% polyps were > 2 cm & remaining 17.9% polyps were between 1-2 cm.21 Asim Qureshi et al study showed that the mean size of polyps were mostly from 0.2 cm-1. 2cm.24 Also Jain M et al showed 93.3 % of the polyps were pedunculated.9

Among histopathological features we reported most of polyp to be tubular adenoma (53.91%) on histopathology followed by Hyperplastic polyp (15.65%) followed by tubulovillous adenoma (13.04%) then by Peutz Jegher polyp (3.48%) and least with Retention polyp (2.61%). Rahul et al and Basnet et al showed most were tubular adenoma in morphology followed by tubulovillous in nature. 21, 22 Chondulo et al and Bafandeh Y et al also showed tubular adenoma to be commonest on histology. 25, 12 The incidence of tubular adenoma reported by Beigh et al. Xianghuayiet et al and Marques et al was 46.67 %, 58.6%, and 42.6% respectively, which was close to 53.91% found in our study.26, 27, 28 While Jain et al, Albasri et al and Wickramasinghe et al studies showed that the commonest histolopathological type of polyp were tubulovillous adenoma (33.5%) followed by tubular adenoma (24.5%). 9, 15, 29

Majority of cases in our study most polyp showed no dysplasia (94.64%) followed by 5.36% of polyp showing high grade dysplasia in form of nuclear stratification and broadening of nuclei. Kumar et al, Wisedopas et al and Mbakop et al also showed in their studies that non-neoplastic polyp constituted a major number of cases (83%, 50% and 87.5%) which is in concordance with our study.10, 30, 31 Our study showed low percentage of dysplasia (5.36%) which was present in equal proportion both in tubular adenoma and tubulovillous adenoma. Similar findings showed in Rahul et al study that high grade dysplasia was seen around 5.8% of polyps but were commonly seen in tubulovillous adenomas then tubular adenomas and also serrated polyps.21 Qureshi et al found that a higher rate of dysplasia was associated with villous (50%) and tubulovillous (62.1%) compared to tubular type (7%).24 Albasri et al concluded that the polyp with villous morphology (95.7%) and tubulovillous (66.7%) structures were strongly associated with high grade dysplasia.15

Conclusion

Colonoscopy is the most important tool in the detection of colonic polyp. In our study most patients had clinical presentation like constipation and rectal bleeding which is most commonly seen in right and left side colorectal carcinoma. Most of the polyps were pedunculated and seen in the left side of colon (descending colon and rectum) which were seen in other previous studies. The histopathological patterns seen in our study were tubular adenoma. High grade dysplasia was rarely seen in our reported polyp cases.

Conflict of Interest

The authors declare no relevant conflicts of interest.

Source of Funding

None.