Elsevier

Gastrointestinal Endoscopy

Volume 59, Issue 2, February 2004, Pages 213-219
Gastrointestinal Endoscopy

Original Article
Clinicopathologic and endoscopic features of colorectal serrated adenoma: differences between polypoid and superficial types

https://doi.org/10.1016/S0016-5107(03)02693-2Get rights and content

Abstract

Background

Serrated adenoma is a distinct histologic colorectal lesion. There are two macroscopic types: polypoid and superficial. The aim of this study was to clarify clinicopathologic and endoscopic differences between polypoid and superficial serrated adenomas.

Methods

An analysis was conducted of the clinicopathologic and endoscopic features for 240 polypoid and 127 superficial serrated adenomas examined by colonoscopy, and the surface pit patterns of 114 polypoid and 64 superficial serrated adenomas examined by magnifying videoendoscopy.

Results

The male:female gender ratio for the polypoid serrated adenomas (3.5:1) was significantly higher than that for the superficial serrated adenomas (1.7:1). Superficial serrated adenomas were significantly larger than polypoid serrated adenomas (mean [standard deviation], respectively, 10.1 [7.9] mm vs. 6.3 [4.6] mm). In the distal segments of the colorectum, polypoid serrated adenomas were more common than superficial serrated adenomas. Granulonodular and lobular appearances at endoscopy were significantly more common for polypoid (23.3%) than for superficial serrated adenomas (7.1%). Pit patterns differed between the lesion types: polypoid serrated adenomas had type IIIL or IV pit patterns; all superficial serrated adenomas had the type II pit pattern. The relative frequency of occurrence of high-grade dysplasia and carcinoma in situ among superficial serrated adenomas (25.2%) was significantly greater than that among polypoid serrated adenomas (9.2%). The tubulovillous growth pattern was significantly more common in polypoid tumors (31.5%) than in superficial tumors (0%).

Conclusions

Polypoid and superficial serrated adenomas have different clinicopathologic characteristics and growth patterns.

Section snippets

Patients and methods

Included in the present study are a total of 367 SAs found in 355 (0.02%) of 15,656 patients (9396 men, 6260 women) examined from January 1992 until December 2001. Patients who did not have total colonoscopy and those with an established diagnosis of familial adenomatous polyposis or inflammatory bowel disease were excluded. All lesions were excised by EMR or electrosurgical snare polypectomy. Serrated adenomas were divided into two types based on their macroscopic appearances: polypoid (n = 240)

Results

The age of patients with polypoid SA ranged from 28 to 88 years with a mean of 59.7 (12.3) years; the age for those with superficial SA ranged from 29 to 74 years, with a mean of 60.8 (11.8) years. The difference in age between the two groups was not significant. The male:female gender ratio was significantly higher for polypoid SAs (187:53) than for superficial SAs (80:47). Polypoid SAs were located in the distal portion of the colorectum more frequently than superficial SAs (p<0.05 in a

Discussion

Some of the results of the present study differ from published data. That is, the male:female gender ratio observed for both polypoid and superficial SAs was higher than that previously reported.1 Superficial SAs were distributed comparatively equally in all parts of the colorectum, whereas polypoid SAs were predominant in the distal colorectum, as found in prior studies.1., 2., 3. It is possible that superficial SAs were not fully examined in prior investigations, which may account for the

Acknowledgements

We thank Dr. Shimamoto MD, PhD, in the department of pathology in our hospital for microscopic examinations and histologic diagnoses.

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