LECTURE

1. Intestinal Polyposis Syndromes.
What is an Intestinal Polyp?
A colorectal polyp is a growth that sticks out of the lining of the colon or rectum. . Polyps
greater than one centimeter have a greater cancer risk associated with them than polyps
under one centimeter. Risk factors include a family history of colon cancer or polyps.Polyps
may also be associated with some hereditary disorders, including:
1-Gardner's syndrome. is an autosomal dominant form of polyposis
characterized by the presence of multiple polyps in the colon together with tumors
outside the colon.The extracolonic tumors may include osteomasof the skull, thyroid
cancer, epidermoid cysts, fibromas as well as the occurrence of desmoid tumors in
approximately 15% of affected individuals.
2-Peutz-Jeghers syndrome, also known as hereditary intestinal
polyposis syndrome, is an autosomal dominant genetic disease characterized by
the development of benign hamartomatous polyps in the gastrointestinal tract and
hyperpigmented macules on the lips and oral mucosa (melanosis) . Peutz–Jeghers
syndrome has an incidence of approximately 1 in 25,000 to 300,000 births
3-Juvenile polyposis. is a syndrome characterized by the appearance of
multiple juvenile polyps in the gastrointestinal tract. These usually begin appearing
before age 20, but the termjuvenile refers to the type of polyp, not to the age of the
affected person.While the majority of the polyps found in Juvenile Polyposis
Syndrome are non-neoplastic, hamartomatous, self-limiting and benign, there is an
increased risk of adenocarcinoma
4-Familial adenomatous polyposis , inherited condition that
causes extra tissue (polyps) in large intestine and in the upper part of small
intestine (duodenum). If untreated, the polyps in the large intestine almost
always become cancerous by age 40.
Most people with familial adenomatous polyposis eventually need surgery to
remove the upper part of the large intestine (colon) to prevent cancer. The
polyps in the duodenum can also develop cancer, but they can usually be
managed by removing them regularly
5-Lynch syndrome (HNPCC), is an inherited condition that
increases your risk of colon cancer and other cancers. Lynch syndrome has
historically been known as hereditary nonpolyposis colorectal cancer
(HNPCC). It is estimate that about 3 out of every 100 colon cancers are
caused by Lynch syndrome.
Families that have Lynch syndrome usually have more cases of colon cancer
than would typically be expected. Lynch syndrome also causes colon cancer
to occur at an earlier age than it might in the general population.

2. •
Symptoms of polyposis
Colonic polyps in children most commonly present with rectal bleeding.
Diagnosis of polyposis
A rectal examination may reveal a polyp that can be felt by the physician. However, the
physical exam is usually normal.
Tests that show polyps:
• Sigmoidoscopy (an internal examination of the lower large bowel (colon), using an
instrument called a sigmoidoscope)
• Colonoscopy (an internal examination of the colon (large intestine), using an
instrument called a colonoscope)
• Virtual colonoscopy
• Barium enema
Treatment
Small polyps can be removed with an electrocautery by colonoscopy .
Large, sessile, soft, velvety lesions in the rectum are usually villous adenomas and these
tumors have a high malignant potential and must be excised completely
Pedunculated polyps and small sessile lesions in the sigmoid and above should be removed
with biopsy forceps or an electrocautery snare passed through the colonoscope.