​Kembara Xtra - Medicine - Colonic Polyps

​Kembara Xtra - Medicine - Colonic Polyps 
Introduction 
Intraluminal colonic tissue growth; most usually sporadic or part of polyposis syndromes; generally slow growing with little potential for malignancy; however, due to the great incidence in the population, resection is generally recommended in order to eliminate risk.
Size classification: – Diminutive 5 mm, small 6 to 9 mm, giant 10 mm Morphologic classification: – Depressed, flat, sessile, or pedunculated Clinical significance: – Over ninety-five percent of colonic adenocarcinomas originate from polyps.

Epidemiology (Incidence and Prevalence) 
In Western countries, non-Caucasian men have a higher incidence of colorectal polyps than Caucasian men do.
Incidence
The prevalence rises with advancing age.
The prevalence is between 15 and 20 percent of all adults, 30 percent of people over the age of 50 in the United States, 6 percent of children, and 12 percent of children who bleed from the lower gastrointestinal tract.


Pathophysiology 
● Mucosal – Neoplastic
○ Adenomatous polyps (tubular >80%, villous 5–15%, tubulovillous 5–15%)  Polyps with serrated edges
 Sessile serrated polyps (SSPs) are prevalent, especially in the proximal colon. They have a low malignant risk if there is no dysplasia but a large malignant potential if there is dysplasia.
Traditional serrated adenomas are not very prevalent; they are more frequently observed in the distal colon; and they have a substantial propensity for malignancy.
- Polyps that are not neoplastic (including hyperplastic polyps, juvenile polyps, hamartomas, and inflammatory pseudopolyps) The risk of hyperplastic polyps developing into cancer is quite low, despite their high prevalence, particularly in the distal colon.
Juvenile polyps, also known as benign hamartomas, are quite frequent in children. They tend to develop in the rectosigmoid region and are not malignant precursor lesions.
● Submucosal (lipomas, lymphoid aggregates, carcinoids)

Genetics
The development of cancer in polyps is caused by the inactivation of tumor suppressor genes such as adenomatous polyposis coli (APC) or mismatch repair genes (MLH1).
● Familial adenomatous polyposis (FAP) is autosomal dominant. Patients virtually always develop colorectal cancer (also known as CRC) by the age of forty.
MUTYH-associated polyposis, often known as MAP, is an autosomal recessive disease that is brought on by biallelic mutations in the MUTYH gene.
● Juvenile polyposis syndrome (JPS) is autosomal dominant.
Between fifty and sixty percent of patients have a mutation in either the SMAD4 or BMPR1A gene. Twenty percent of patients will have developed CRC by the age of 35.

factors of danger 
Inflammatory bowel disease is associated with a decreased prevalence of colon polyps (but with a higher risk of colon cancer). Other risk factors for colon cancer include a family history of intestinal polyposis, polyps, or CRC; advancing age; being male; high-fat, low-fiber diet; cigarette use; excessive alcohol intake: more than eight drinks a week.

Prevention
Eat a diet low in fat and rich in fiber, don't smoke, and cut back on the amount of alcohol you drink.
The use of nonsteroidal anti-inflammatory drugs (NSAIDs) and calcium is linked to a lower risk of developing polyps and having existing polyps return.
There was no significant reduction in the risk of developing colorectal cancer associated with the use of azathioprine, 6-mercaptopurine, folate, calcium, multivitamins, or statins.

Conditions That Often Occur Together 

Hereditary polyposis syndromes include: Adenomatous – FAP Classic (CFAP) Attenuated (AFAP) – MAP – FAP variants: Adenomatous – FAP Classic (CFAP) Attenuated (AFAP)
○ Gardner syndrome ○ Turcot syndrome
-- Peutz-Jeghers syndrome (PJS) -- a hamartomatous condition
– JPS – Familial juvenile polyposis – Cowden syndrome
ALERT
Even though juvenile polyps are not premalignant, JPS is associated with an increased risk of colorectal cancer.

Presenting History Generally asymptomatic; painless rectal bleeding, bright or dark red, mixed with stools, dripping, or on wiping; diarrhea or mucous stool; abdominal pain; constipation; chronic bleeding, resulting in iron deficiency anemia; McKittrick-Wheelock syndrome; large hypersecretory rectosigmoid villous adenoma, resulting in persistent severe diarrhea; electrolyte disorder; dehydration; and pre 
Social history and family genealogy


Clinical Examination Typically normal; digital rectal examination (DRE) may reveal rectal polyps as prolapsed or palpable masses; fecal occult blood test (FOBT) performed using DRE is less accurate than FOBT performed using stool that is passed spontaneously.

Initial Tests (lab, imaging) Laboratory Tests Initial Tests
CBC; anemia with chronic bleeding Basic metabolic panel; electrolyte problem with hypersecretory adenomas FOBT; an insensitive screening test due to the fact that tiny polyps typically do not bleed: - Guaiac (gFOBT) — employs a chemical indicator that undergoes a change in color when blood is present. – The immunochemical test, often known as the fecal immunochemical test (FIT), employs antibodies directed against human hemoglobin. – The stool DNA test is more sensitive but less specific than the FIT.

Diagnostic Methods and Other Procedures
Colonoscopy is the gold standard test for the detection of polyps, and it also allows for concurrent polypectomy. However, colonoscopy is not a perfect screening test since it has a higher miss rate for right-sided colon polyps, smaller polyp size, worse quality of colon prep, and less endoscopist experience. 
Computed tomographic colonography, often known as CTC, has a lower sensitivity when dealing with flat polyps and calls for proper bowel preparation.
● Double-contrast barium enema
 ● Colon capsule endoscopy
Enhanced optical technologies have the potential to distinguish neoplastic colonic lesions from non-neoplastic colonic lesions.
Enhanced optical technologies include the following: – Narrow-band imaging endoscopy (also known as narrow-spectrum endoscopy)
– Image-enhanced endoscopy (i-scan)
- Fujinon intelligent chromoendoscopy (FICE) – Confocal laser endomicroscopy (CLE)
Patients who have more than 10 colorectal adenomas ought to go through genetic testing for APC and MUTYH.

The Interpretation of Tests
a tubular adenoma is characterized grossly by its polypoid appearance and microscopically by its dysplastic epithelium and tubular architecture.
● Villous adenoma:
Grossly, it is sessile, and microscopic examination reveals dysplastic epithelium with fingerlike projections.
adenomas that are classified as tubulovillous have an architecture that is a mix of tubular and villous structures.
Hyperplastic colonic mucosa is what makes up hyperplastic polyps in the colon.
● Hamartomatous polyps include muscularis mucosa.

 Juvenile polyp - Gross: pedunculated, smooth red mass, one centimeter to three centimeters in diameter 


Surgical Procedures Including Colon Polypectomy for Diagnostic and Therapeutic Purposes: Endoscopic submucosal dissection for pedunculated polyps, snare polypectomy with electrocautery for pedunculated polyps, and endoscopic mucosal resection for sessile polyps are the three procedures that are used to remove polyps.
Colorectal surgery; preventative in FAP and MAP, as well as in cases when there are a significant number of polyps or chronic bleeding: – Proctocolectomy with an ileal pouch anal anastomosis – Ileorectal anastomosis following total colectomy
NSAIDs and calcium have been shown to have the potential to lower the occurrence of polyps as well as their recurrence in patients diagnosed with FAP and MAP.

Colonoscopy should be repeated in less than ten years if there are no polyps or if they are distal and less than ten millimeters in size.

 3 to 5 years in hyperplastic polyps that are less than 10 millimeters; 7 to 10 years if there are 1 to 2 small tubular adenomas that are less than 10 millimeters.

 3 to 5 years if there are 3 to 4 tubular adenomas that are less than 10 millimeters in size.
3 years if there are 5 to 10 tiny tubular adenomas (less than 10 millimeters in size).
1 year if there are more than 10 adenomas 3 years if one or more adenomas are less than 10 millimeters 3 years if one or more adenomas have tubulovillous or villous features of any size or have high-grade dysplasia (HGD) 6 months if the adenoma or SSP is less than 20 millimeters and piecemeal resection is performed  

 3 to 5 years if there are 3 to 4 little SSPs (less than 10 millimeters).
3 years if 5 to 10 small SSPs (less than 10 millimeters) 3 years if SSP less than 10 millimeters or with dysplasia or a conventional serrated adenoma Different consideration is provided for polyps that fulfill criteria for serrated polyposis syndrome

Monitoring of the Patient
Screening with colonoscopy for colorectal cancer can begin at age 45 or earlier for those who are at higher risk. It is recommended by the American Cancer Society (ACS), the American College of Gastroenterology (ACG), and the United States Preventive Services Task Force (USPSTF) that people who have an average risk for colorectal cancer start screening at the age of 45 and continue through the age of 75. This age range may be extended to 85 years depending on life expectancy and overall health.
If a person's life expectancy is less than ten years, screening should be discontinued.
Screening for extracolonic symptoms, such as thyroid cancer, desmoid tumors, and gastroduodenal polyposis, should be performed every six months to five years in CFAP and AFAP patients.
Lifetime testing of individuals within families to identify mutant carriers (2) [C]:
- In the CFAP, sigmoidoscopy or colonoscopy should be performed once every one to two years beginning at the age of 10 to 11 years. - For those enrolled in the AFAP and MAP programs, colonoscopies are recommended every 1 to 2 years, beginning between the ages of 18 and 20. 
Following colon surgery, it is recommended to perform monitoring of the pouch (every 6 months to 5 years) or the rectum (every 6 months to 12 months).
After the age of 12 years, first-degree relatives of people diagnosed with JPS are required to undergo screening with colonoscopy and upper endoscopy.
It is advised that a genetic study be performed on any patient who has accumulated more than 10 adenomas over the course of their lifetime.

Nutrition
(not enough proof) diets that are low in fat and high in fiber

The significance of the colonoscopy as a diagnostic method

Regression of the tumor or stable size are the two most likely outcomes, and these outcomes are more likely to occur in individuals with small hyperplastic polyps who are taking NSAIDs. 
There is a recurrence of juvenile polyps in 45% of children who have numerous polyps and in 17% of children who have solitary polyps.
These are some of the risk factors for colon cancer: - Polyp pathology that is adenomatous, serrated, has HGD, and has greater than 25 percent villous histology
polyp size greater than one centimeter in diameter polyps found in the proximal colon polyp count greater than three
Recurrence rates of less than ten percent after polypectomy. Lingering cancer as a result of ineffective endoscopic excision of precancerous lesions. 

Complications 
Polyps: a precancerous step toward malignancy 
Polypectomy: bleeding between 2 and 11%, perforation between 0 and 1%, higher with endoscopic submucosal dissection Colonoscopy: risks associated to both the anesthetic and the treatment itself

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