CRC Flashcards
(15 cards)
Discuss the difference between average risk and high risk family
history for colorectal cancer screening.
Average Risk
1-No personal or family history of colorectal cancer or advanced adenomas.
2-No history of inflammatory bowel disease (like Crohn’s disease or ulcerative colitis).
3-No known genetic syndromes (e.g., Lynch syndrome or familial adenomatous polyposis).
*Screening Recommendation:
Start regular screening at age 45 (as per updated guidelines).
Use standard options like colonoscopy every 10 years or stool-based tests (FIT, FOBT, or stool DNA tests).
High Risk
*Single first-degree relative with CRC or advanced adenoma diagnosed at age ≥ 60 years
o Start screening at age 40, patients may choose any test, follow regular surveillance intervals.
Single first-degree relative with CRC or advanced adenoma diagnosed at age < 60 years, or ≥2 first-degree
relatives with CRC or advanced adenoma regardless of age.
o Start screening at age 40 (or 10 years younger than the age of diagnosis of the youngest affected
relative), offer colonoscopy first. Offer FIT if patient refuses colonoscopy. Repeat colonoscopy
every 5 years if normal.
When to stop colon cancer screening
Guidelines recommend stopping routine screening at age 75.
Potential malignant colonic polyps
The malignant potential of colon polyps depends on several key factors:
1-Histologic Type
2-Size
3-site and numbers
4-Grade of dysplasia
Potential malignant colonic polyps
A-Histologic Type (Asi)
1-Adenomatous polyps (adenomas): Premalignant, with potential to progress to colorectal cancer.
*Tubular adenomas: Most common, lower risk.
*Tubulovillous adenomas: Intermediate risk.
*Villous adenomas: Highest malignant potential.
2- Serrated polyps:
*Hyperplastic polyps: Usually benign (except in proximal colon).
*Sessile serrated adenomas (SSAs) and traditional serrated adenomas (TSAs): Premalignant.
3-Inflammatory and hamartomatous polyps: Generally non-neoplastic, low or no malignant potential (e.g., in Peutz-Jeghers or juvenile polyps).
Potential malignant colonic polyps
B-Size
Risk increases with size:
<1 cm: low risk
1–2 cm: intermediate risk
> 2 cm: high risk
Potential malignant colonic polyps
- Dysplasia Grade
High-grade dysplasia in a polyp indicates a higher risk of malignant transformation.
Potential malignant colonic polyps
- Number and Distribution
Multiple polyps or polyps in the proximal colon may indicate a higher cumulative cancer risk.
Cancer colon screening
1-FAP:
By annual sigmoidoscopy since age of 10-12 years till collectomy
2-HNPCC(Hereditary Non Polyposis Colorectal Carcinoma)(Lynch ):
Annual colonoscopy since age of 20-25 years old or 10 years younger than the age of youngest diagnosed patients.
3-IBD
Annual colonoscopy 8 years after diagnosis of pancolitis and 15 years after diagnosis of Lt sided colitis
4-General population:
Start at age of 45-50
* annually FOB or colonoscopy every 10 years
Ogilvie syndrome “acute colonic pseudo-obstruction,”
Definition
It is a condition where there is a large bowel distention leading to symptoms and signs of colonic obstruction inspite of there is no mechanical obstruction.
*It typically affects the cecum and right colon.
Ogilvie syndrome “acute colonic pseudo-obstruction,”
Causes
The cause of Ogilvie syndrome is usually related to a disruption in the normal peristalsis (movement of the intestines), leading to colonic dilation. This can be triggered by factors like:
1-Post-surgical states (especially after abdominal or pelvic surgery).
2-Burns
3-Trauma or injury
4-Infections
5-Electrolyte imbalances (such as low potassium or calcium)
6-Medications (like opiates or anticholinergics)
7-Neurological conditions (such as Parkinson’s disease)
Ogilvie syndrome “acute colonic pseudo-obstruction,”
Management
1-Exclude cl difficle, mechanical obstruction
2-Asses for clonic ischemic and perforation
3-Npo
4-Neostigmine
5-colonoscopic decompression
If:No response to neostigmine,there is contraindications for neostigmine,psudoobstruction more than 5 days ,cecum diameter more than 10 cm
6-cecostomy in refractory cases
7-coloctmy if performed or severe ischemia
Neostigmine
*Mechanism of action:
Neostigmine → Acetylcholine esterase inhibitor → ↑ Acetylcholine level → ↑ motility
*C.I
1-Mechanical obstruction
2-Ischemia
3-Pregnancy
4-creat >3
*Dose…
2.5 mg iv over 5 minutes and monitor for 30 minutes ,atropine should be beside patient if svere bradycardia occured.
ICU patient with obstipation and abdominal distension, CT reveals no evidence
of obstruction but demonstrates a cecal diameter > 10 cm.
Ogilive syndrome
