This document defines and classifies colorectal polyps. It discusses that polyps can be benign or malignant, and classified by shape (pedunculated or sessile) or histology (epithelial or mesenchymal). Malignant polyps have characteristics like large size (>1cm), villous or tubulovillous histology, high grade dysplasia, or multiple polyps which increase cancer risk. The Haggitt criteria classify cancer invasion in polyps from Level 0 (in situ) to Level 4 (invading submucosa below stalk). Surveillance colonoscopy intervals depend on polyp characteristics, ranging from 1-5 years. Polypectomy can treat early cancers but resection

1. Colorectal polyp
definition,types,colonscopic survillence
National cancer institute –misrata
Surgery department
Dr . Mohamed alhashmi sidoun

2.  Colorectal polyp is projecting mass into the
lumen of bowel above the surface of epithelium.
 Polyp is word descriptive for the shape of lesion
(not related to the pathological process)
 Polyposis :multiple polyps
 Polypoid
 Colorectal polyps are considerd slow growing
tumour
 The term “malignant polyp” refers to a macroscopically
benign appearing adenoma in which the invasive
carcinoma is detected after histologic examination of the
resected specimen.

3. Classification of polyps
 According to the shape
 According to the histology

4. According to the shape
1. Pedunculated ( with stalk)
2. Sessile (no stalk ,no neck )

5. According to the histopathology
Polyps such as hyperplasic,juvenile and
inflammatory polyps have no malignantpotential,
although polyps do have malignant potentia
Type Benign Malignant
Epithelial Neoplasma Adenocarcinoma
Inflammatory
Hamartoma
Metaplastic
mesenchymal Lipoma Sarcoma
Fibroma lymphoma
Leiomyoma
haemangioma

6. Neoplasma (1/3 of crc have benign
polyp)
 Tubular adenoma :
60-80 %
usually pedunculated polyp
 Villous (finger like projection):
5-10 %
usually sessile
more precancerous cellular changes (sever atypia)
 Tubulovillous adenoma :
10 – 25 %

7. The prognostic factors :
(polyps transformed to carcinoma)
The presence of poor prognostic features should
lead the physician to favor colectomy
1. Polyp size more than 1 cm are found to harbor cancers more
than the cells
size less than 4 mm usually hyperplastic (no malignant
changes but should be excised
sessile polyp more than 2 cm usually villous with high
malignant changes and high recurrence rate
2.Shape of the polyp : the invasion of adenocrcinoma in
pedunculated polyp need travel during head,neck,stalk
before reaching the submucosa (polypectomy not
appropriate) contrast with sessile where just travel the
basement membrane

10. 3.Histopatholo of the polyp :
the villous subdivision are associated with the highest
malignant potential because they have the largest
surface area ,no stalk and no neck.
2 cm sized tubular adenoma _35%risk of malignancy
2 cm sized villous adenoma _50 % risk

11. 4.Multiple polyps more prognostic than single (familial
adenomatous polyposis) 100% risky
5. Missed polypectomy or patient refuse even smaller
one(polypectomy of small polyps decreases the cancer
incidence up to 70%.
6.risk of age ,family history,smoking
(the peak incidence of crc is 60 years of age ,the peak
incidence of colorectal polyp discovering is 50 years of
age ,this means 10 years time span for progression )

12. Hagitt criteria
 In the United States, the prevalence of
adenomatous polyps found during
colonoscopic evaluation ranges from 25 to
41%, and of these, 2 to 5% contain invasive
malignancy.
 Endoscopic resection by polypectomy has been
shown to be sufficient for management of
certain polyps containing cancer.

13.  Depth of invasion has been shown to correlate with the
risk of lymph node metastasis. Other unfavorable
histologic features include lymphovascular invasion, poor
differentiation, inability to assess margin (piecemeal
resection), and positive resection margin (<2 mm); these
are important factors to consider in management. For
these patients formal oncologic surgical resection is
indicated.
 Polypectomy is usually performed during colonoscopy
using snare polypectomy techniques. High-quality
polypectomy is the complete excision of the polyp, which
should include the entire stalk to its base. The
submucosa of the bowel wall should be included to allow
optimal histologic evaluation of the margins.

14.  Level 0 indicates carcinoma in situ or intramucosal
carcinoma. These lesions are not invasive, and therefore
behave as benign adenomas due to an absence of
lymphatics in the mucosal laye
 Level 0 Carcinoma in situ or intramucosal carcinoma. Not
invasive.
Level 1 Carcinoma invading through muscularis mucosa
into submucosa, but limited to the head of the polyp.
Level 2 Carcinoma invading the level of the neck of the
adenoma.
Level 3 Carcinoma invading any part of the stalk .
Level 4 Carcinoma invading into the submucosa of the
bowel wall below the stalk of the polyp, but above the
muscularis propria.

15.  Level 1 (above the junction between the adenoma and
the stalk). Colorectal resection is not necessary if the line
of resection of the stalk is free , routine follow-up is
needed
 Level 2: carcinoma invading to the level of the
neck of adenoma (the junction of adenoma and stalk).
Surgical Resection is not necessary if the margin of
of the stalk is free and endoscopic follow-up is
needed.

16.  Level 3: carcinoma invading any part of the stalk.
A free margin of resection precludes the necessarily
for any formal colorectal resection.
 Level 4: carcinoma invading the submucosa of
bowel wall below the stalk of the polyps but above the
muscular propria. This is invasive cancer and a formal
bowel resection is necessary,
 By definition all sessile polyps with invasive carcinoma
are level 4. Hence, resection of bowel wall is indicated.

17. Colonoscopy surveillance and surveillance
intervals for colorectal polyps
 polyp sized less than 1 cm detected on colonoscopy
,otherwise normal ,h/p of this polyp was hyperplastic _go
home and colonoscopy repeated after 10 years .
 If the polyp was large sessile ,complete excision done this
patient need colonscopy follow up after 3_months
 Resectional polypectomy of malignant non invasive polyp
__need follow up colonscopy after 12 months ,after this
period as for ordinary adenoma
 Resectional polypectomy of high grade dysplasia _colonscopy
repeated after 3 months if normal repeated at 1 year if normal
5 years
 Resected of Single tubular adenoma less than 1 cm no need
for follow up

18.  Resection of adenoma +3 polyps +previous h/o
other cancer __need colonscopy every 5 years
 For patient who have had surgical resection of
colon cancer need follow up with colonscopy
every 6 months for the initial 2 years
 Low risk (size <1cm,no.1-2 )repeated after 5
years
 Intermediated risk (size >1cm ,no. 3-4 ) :after 3
years
 High risk(>1cm ,no. more than 5 ) : after one year
N.b the three risk degrees are exchangable .

19. References :
Current medical diagnosis and treatment 2008
Muir`s textbook of pathology
Nms surgery (fifth edition)
Website adress : clinics in colon and rectal
Surgery .