Polyposis syndromes

Question 1

What are the hereditary type Polyposis syndromes?

Answer 1

1. Hereditary nonpolyposis colorectal cancer (HNPCC)
2. Familial Adenomatous Polyposis syndrome (FAP)
   > classic FAP, Gardner Syndrome, Turcot syndrome
3. Bannayan–Riley–Ruvalcaba syndrome
4. Cowden syndrome
5. Peutz-Jeghers syndrome
6. tuberous sclerosis
7. Juvenile polyposis syndrome (25% hereditary with AD inheritance)

Question 2

What are the non-hereditary type Polyposis syndromes?

Answer 2

1. serrated polyposis syndrome (SPS), also known as hyperplastic polyposis syndrome
2. Cronkhite-Canada syndrome
3. Juvenile polyposis syndrome (75% non hereditary)

Question 3

What are the adenomatous type Polyposis syndromes?

Answer 3

1. Familial adenomatous polyposis syndrome (FAP)
2. Gardner syndrome

Question 4

What are the hamartomatous Polyposis syndromes?

Answer 4

1. Juvenile polyposis syndrome
2. Bannayan–Riley–Ruvalcaba syndrome
3. Cowden syndrome
4. Peutz-Jeghers syndrome
5. Cronkhite-Canada syndrome

Question 5

Features of HNPCC (Lynch Syndrome)

Answer 5

• Caused by microsatellite instability from DNA mismatch repair.
• Colon carpet of adenomatous polyps
• Increased risk of other cancers: endometrial, gastric, small bowel, liver, biliary

Question 6

Features of Gardner Syndrome “DOPE”

Answer 6

1. Desmoid tumors of the mesentery and anterior abdominal wall
2. Osteomas, multiple
3. Polyposis of small and large bowel
4. Epidermal cysts
5. • Poor dentition from supernumerary teeth, odontomas and dentigerous cysts
     + duodenal tumours / ampullary carcinoma
     + papillary thyroid carcinoma

Autosomal dominant inheritance in the FAP gene (chromosome 5q) in a majority of patients but with 20% of cases resulting from new mutations. Extracolonic features often precede the diagnosis of colonic polyps.

Question 7

Features of Peutz-Jaghers syndrome

Answer 7

• Hamartomatous polyps usu in small bowel, which can serve as lead points for intuss
• Mucocutaneous pigmentation, esp in perioral/lips and gums
• Increased risk of many cancers (upper GI, ovary, thyroid, testis, pancreas, breast).

Question 8

Features of Cowden Syndrome (AKA multiple hamartoma syndrome, is characterised by multiple hamartomas throughout the body and increased risk of several cancers.)

Answer 8

1. Increased risk of breast and thyroid (follicular type) cancer, and CNS-association with Lhermitte Duclos disease
2. GI hamartomatous polyps (small and large bowel)
3. Thyroid abnormalities: goitre, adenomas
4. Breast: FCC
5. Testicular lipomatosis

Autosomal dominant inheritance with variable penetrance. A gene locus for the disease has been identified on chromosome 10q22-23, a mutation of the PTEN gene.

Question 9

Features of FAP

Answer 9

• Colonic carpet of premalignant adenomatous polyps -> usually recommended for prophylactic total colectomy
• Stomach hamartomas
• Duodenal adenomas
• Periampullary carcinoma
• Desmoid tumours

Question 10

Features of Turcot Syndrome (Diarrhea and Seizures!)

Answer 10

• Diarrhoea – colonic polyps (subject to the adenoma-carcinoma sequence and thus most patients develop cancer before the reach 40 years of age.)
• Seizures – supratentorial glioblastomas or medulloblastomas.