3. Definition
• Polyp is a
nonspecific clinical
term that describes
any projection from
the surface of the
intestinal mucosa
regardless of its
histologic nature.
4. Colorectal polyps may be classified as
1.neoplastic (tubular adenoma, villous adenoma,
tubulovillous adenomas, serrated adenomas/ polyps),
2.hyperplastic,
3.hamartomatous (juvenile, Peutz-Jeghers, Cronkite-
Canada),
4.inflammatory (pseudopolyp, benign lymphoid polyp)
6. Neoplastic Polyps
• Adenomatous polyps are common, occurring in up to 25% of older than 50
years in the United States.
• The risk of malignant degeneration is related to both the size and type of
polyp.
• Tubular adenomas are associated with malignancy in only 5% of cases,
• whereas villous adenomas may harbor cancer in up to 40%.
• Tubulovillous adenomas are at intermediate risk (22%).
• Invasive carcinomas are rare in polyps smaller than 1 cm;
• the incidence increases with size.
• The risk of carcinoma in a polyp larger than 2 cm is 35% to 50%.
7. Complications
• include perforation and bleeding.
• A small perforation (microperforation) in a fully prepared, stable
patient may be managed with bowel rest, broadspectrum antibiotics,
and close observation.
• Signs of sepsis, peritonitis, or deterioration in clinical condition are
indications for laparotomy.
• Bleeding may occur immediately after polypectomy or may be
delayed.
9. Hyperplastic Polyps
Hyperplastic polyps are extremely common in the colon.
These polyps are usually small (<5 mm) and show histologic
characteristics of hyperplasia without any dysplasia.
They are not considered premalignant, but cannot be
distinguished from adenomatous polyps colonoscopically and
are therefore often removed.
In contrast, large hyperplastic polyps (>2 cm) may have a
slight risk of malignant degeneration.
10.
11. Sessile
Serrated polyp
• Serrated polyps: umbrella term
for hyperplastic polyps, sessile
serrated lesions, traditional
serrated adenomas and mixed
polyps
14. • In contrast to adenomatous and serrated polyps,
hamartomatous polyps (juvenile polyps) usually are not
premalignant.
• These lesions are the characteristic polyps of childhood
but may occur at any age.
• Bleeding is a common symptom, and intussusception
and/or obstruction may occur.
• Because the gross appearance of these polyps is identical
to adenomatous polyps, these lesions should also be
treated by polypectomy.
• In contrast to adenomatous polyposis syndromes, these conditions are often associated
with mutation in PTEN
15.
16. Familial juvenile polyposis
• is an autosomal dominant disorder in which patients
develop hundreds of polyps in the colon and rectum.
• Unlike solitary juvenile polyps, these lesions may
degenerate into adenomas and eventually carcinoma.
• Annual screening should begin between the ages of 10 and 12 years.
• Treatment is surgical and depends in part on the degree of rectal
involvement.
• If the rectum is relatively spared, a total abdominal
colectomy with ileorectal anastomosis may be
performed with subsequent close surveillance of the
retained rectum.
20. Inflammatory Polyps (Pseudopolyps)
. Inflammatory polyps occur most commonly in the
context of inflammatory bowel disease, but may
also occur after amebic colitis, ischemic colitis, and
schistosomal colitis.
. These lesions are not premalignant, but they cannot
be distinguished from adenomatous polyps based
on gross appearance and therefore should be
removed.
• Polyposis may be extensive, especially in patients
with severe colitis, and may mimic FAP.
22. • Level 1 (carcinoma limited to the head of the polyp).
• Level 2 is where carcinoma invades to the level of the neck (the junction of the head and stalk) of
the adenoma.
• Level 3 is carcinoma invading any part of the stalk.
• Level 4 is where carcinoma invades into the submucosa of the bowel wall below the level of the
stalk.
• In the sessile adenoma a stalk is absent and so, by definition, the lesion is defined as being level
4. divided according to Kikutchi
33. In situ
• Polyps containing carcinoma in situ (high-grade dysplasia) carry no risk of lymph node metastasis.
• However, the presence of high-grade dysplasia increases the risk of finding an invasive carcinoma within the
polyp. For this reason, these polyps should be excised completely, and pathologic margins should be free of
dysplasia.
• Most pedunculated polyps and many sessile polyps may be completely removed endoscopically.
• In cases where the polyp cannot be removed entirely, a segmental resection is recommended.
34. Invasive
• Occasionally a polyp that was thought to be benign will be found to harbor invasive carcinoma after
polypectomy.
• Treatment of a malignant polyp is based on the risk of local recurrence and the risk of lymph node
metastasis.
• The risk of lymph node metastases depends primarily on the depth of invasion.
35. Invasive carcinoma in the head of a
pedunculated polyp with no stalk involvement
carries a low risk of metastasis (<1%) and may
be completely resected endoscopically.
For sessile polyps, the depth of invasion
predicts risk of lymphovascular spread. A
recent classification stratifies risk by depth of
submucosal spread. Superficial lesions
(submucosa 1; Sm1) are low risk, whereas Sm2
and Sm3 are intermediate and high risk.
36. Indications of
segmental resection
• Lymphovascular invasion,
• poorly differentiated histology,
• tumor budding,
• tumor within 1 mm of the resection
margin greatly increases the risk of local
recurrence and metastatic spread.
• Invasive carcinoma arising in a sessile
polyp extending into the submucosa
