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محاضرات عين شمس
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Colorectal Polyps
Ahmed A Abou-Zeid
Professor of Surgery
Ain Shams University
What is a Polyp
• Any lesion that is elevated above the mucosal surface of the bowel
Classification• Neoplastic
– Single• Adenomatous polyps• Connective tissue polyps (fibroma, lipoma, leiomyoma,
lymphoma)
– Polyposis Syndromes• FAP• HNPCC
• Non- neoplastic• Hamartomas• Metaplastic polyps• pseudopolyps
Adenomatous polyps
• Tubular adenoma
• Tubulovillous adenoma
• Villous adenoma
Adenomatous polyps
Tubular Adenoma Villous Adenoma
Adenomatous Polyps Clinical Picture
• Symptomless
• Bleeding
• Discharge
• Prolapse
• Obstruction/Intussusception
• Hypokalemia/Hypoproteinemia
Polyp - Cancer Sequence
• Circumstantial evidence– Similar anatomical distribution– Adenomas can harbour foci of carcinoma – Polyp patients are 8-10 years younger– 30% of CRC have synchronous polyps– Metachronous cancer is twice as high in
those cancers with associated polyps– Prophylactic polypectomy decrease incidence
of subsequent cancer
Adenoma-Carcinoma Sequence
Normal
Dysplasia
Adenoma
Carcinoma
Suspicious Polyp
• Size
• Age of polyp
• Histology
Initial ManagementEndoscopic Procedures
Endoscopic Polypectomy
Pedunculated Sessile
Endoscopic Submucus Resection
Initial ManagementTransanal Procedures
Endoanal Submucus Resection
Transanal Endoscopic Microsurgery (TEM)
Initial ManagementAbdominal Procedures
• Colotomy/Colectomy• Proctotomy/Proctectomy
The Polyp With a Malignant Focus
Management of Malignant Polyp
• Polypectomy- Pedunculated- Well differentiated- In Head or stalk,
away from resection margin
- No vascular or lymphatic invastion
- Clear resection margins
• Radical Resection
- Sessile
- Poor differentiation
- Low in stalk
- Vascular or lymphatic invasion
- Involved resection margin
Further Management of Malignant Polyp
Radical Resection
• Site of resection entitled by site of the polyp
• Radicality of resection entitled by extent of the polyp
• India ink injection in the era of laparoscopic surgery
Follow Up After Polypectomy
• Benign polyp - Yearly endoscopy after positive complete clearance- Three yearly endoscopy after negative complete clearance- Five yearly therafter
• Malignant polyp - Follow guidelines of cancer management
Metaplastic Polyps
• Also known as hyperplastic polyps• Usually minute (2-5mm), plaque like,
same colour of mucosa• Asymptomatic, do not turn malignant• Elongated tubules, scanty goblet cells,
hyperplastic cells at the base of crypts• Management depends on individual
policy
Hamartomatous Polyps• Juvenile polyps
• Peutz-Jeghers polyps
Juvenile Polyps• Seen in infants and children less than 10 y• Mostly situated in the rectum• Usually stalked, head covered by granulation tissue• Cut surface shows dilated cystic spaces, bulk of
polyp made up of connective tissue full of acute & chronic inflammatory cells
• Rectal bleeding, polyp prolapse• Not pre-malignant• Treatment by colonoscopy & polypectomy
Peutz Jeghers Syndrome
• Autosomal dominant inheritance• Pigmentation• Polyps• Symptoms of rectal bleeding and recurrent
intussusception• Debate considering the malignant potential• Conservative management versus more
aggressive endoscopic management
Peutz Jeghers Syndrome
Inflammatory Polyps
• Accompany Chronic inflammatory process of the bowel
• Composed of oedamatous mucosal tags
• Not premalignant
• Treatment of the cause
Inflammatory Polyps
Connective Tissue Polyps
Submucuos Lipoma
Connective Tissue Polyps
• Can be benign or malignant
• Size dictates symptomatology in benign lesions
• Commonly present by obstructive symptoms
• Treatment: Segmental resection
Familial AdenomatousPolyposis
• Autosomal dominant inheritance• Mutation in APC gene• Easily recognized by its phenotypic
features– CR polyps and cancer– Extracolonic lesions
• 100% penetrance• 1 in 8,300 to 1 in 14,025 live births
Familial AdenomatousPolyposis
FAP/Extracolonic Lesions
• Desmoids
• CHRPE
• Duodenal adenomas
• Gastric glandular hypertrophy
• Osteomas/Neuromas
• Other tumours
FAP/Extracolonic Lesions
CHRPE Intra-abdominal Desmoid
FAP/Diagnosis
• Clinical diagnosis– Colonic lesions
– Extra-colonic lesions
• Sigmoidoscopy/Colonoscopy
• Genetic diagnosis
• Surveillance
FAP/Treatment
• Prococolectomy/ Brook’s ileostomy
• Restorative proctocolectomy
• Total colectomy/ileorectal anastomosis
HNPCC• Characterized by
– Autosomal dominant inheritance– Mutation in MMR gene– Early onset CR cancer and polyps– Extracolonic cancers
• Diagnosis: Less evident phenotypic features– Family history criteria– Pathology criteria– Genetic criteria
Family History
• Amsterdam criteria
– CRC in 3 family members
– One member 1st degree relative to other two
– Two successive generations
– One cancer diagnosed less than 40
– FAP excluded
• Others (less strict criteria)
Pathology Criteria
• Young age of onset
• Right sided tumors
• Multiple colonic tumors
• Extra-colonic tumors
• Aggressive histopathology features
• Good prognosis
Genetic Criteria
• Disordered mismatch repair genes– hMLH1– hMSH2– hPMS1– hPMS2– hMSH3– hMSH6
Extracolonic Tumours in HNPCC
• Small intestine
• Endometrium
• Urothelium
• Biliary tree
• Gastric mucosa
• Others
Treatment of HNPCC
• Total colectomy/ileorectal anastomosis
• Restorative proctocolectomy
• Surveillance