Polyps and Adenocaricnoma Flashcards
What is a sessile polyp vs peduncuated?
- Sessile is without a stalk
- Pedunculated is with a stalk
Where are hyperplastic polyps predominantly found?
- left colon (sigmoid and rectum)
- usually 6-7th decade
What causes hyperplastic polyps?
- result from decreased epithelial cell turnover and delayed shedding of surface epithelial cells leading to “piling up” of goblet and absorptive cells.
What can a hyperplastic polyp be a clue of?
Presence of adjacent clinically important mass or inflammatory lesion
What syndrome can an inflammatory polyp be a part of?
- Solitary rectal ulcer syndrome
- Rectal bleeding
- Mucus disscharge
- Anterior rectal wall location
What type of polyp and its associated syndromes are associated with increased cancer riwsk?
- Hamartomatous polyps
What is a juvenile polyp?
- Sporadic or syndromic
- Majority occur under 5
- Rectal location predominates
Juvenile polyp symptomS?
- rectal bleeding
- Intussusception
- Intestinal obstruction
- Polyp prolapse
- Extraintestinal manifestations
what is Peutz-Jeghers syndrome?
- AD syndrome presenting at 11 yo with multiple GI hamartomatous polyps and mucutaneous hyperpigmentation
Where does Peutz Jeghers syndrome occur?
Small intestine
What syndrome is associated with intussusception being fatal and has a LOF mutation in STK11 in ~50% of patients, and increased risk of multiple malignancies?
Puetz Jeghers syndrome
What are the most common neoplastic polyps?
Adenomatous polyps
What are adenomas?
Intraepithelial neoplasm that ranges from small often pedunculated poolyps to large sessile lesions
When do adenomatous polyps develop, who do they occur in more, and what are they precursors to?
- Develop in 30% by 60 yo
- M>F
- Precursors to colorectal adenocarcinoma
What are the hallmarks of colorectal adenomas?
- nuclear hyperchromasia
- elongation
- stratification
What is sessile serrated polyposis cancer syndrome?
- rare disorder characterized by presencec of multiple serrated polyps in the colon and increased persosnal and familial risk of colorectal cancer
What is FAP?
- AD disorder in which patients developnumerous colorectal adenomas as teenagers
- Caused by somatic mutation in APC gene
What is one of the extraintestinal manifestations of FAP?
Congenital hypertrophy of the retinal pigment epithelium
When does colonic adenocarcinoma peak? What are the risk factors?
- 60-70 yo
- low fiber, high fat, refined carbs
What are the two genetic pathways for colonic adenocarcinoma?
- APC/B-catenin/Wnt path
- Microsatellite instabililty (MSI) path
What is the classic sequence of gene mutations in sporadic colon cancers?
- APC
- APC B-Catenin
- K-RAS
- TP53
- Telomerase
How many copies of APC need to be lost for an adenoma to arise?
Both, it is a component of the WNT path that controls cell growth and differnetiation
What is Lynch syndrome?
- Hereditary non polyposis colorectal cancer
- caused by inherited mutations in mismatch repair genes that encodes proteins responsible for detection excision and repair
- Cancers occur at younger age and are often located in ascending colon
How are adenocarcinomas located in the colon?
- Usually distributed approximately equally over entire length of colon
- on proximal colon grow polypoid exophytic mass along one wall-rarely causes obstruction
- in distal colon they are annular lesions that produce napkin ring constrictions
