Gastrointestinal Tumours Flashcards
what is associated with squamous cell carcinoma of oesophagus?
- diet (trace material and vitamin deficient)
- fungal contamination of food
- nitrites/nitrosamines
- alcohol/smoking
risk factors for squamous cell carcinoma of the oesophagus
- GORD
- lye stricture
- irradiation
from which condition do most of the adenocarcinomas of the oesophagus arise?
Barrett’s, prolonged GORD
what is the precursor of adenocarcinoma?
high grade dysplasia
what other tumours can occur in the oesophagus?
- smooth muscle (leiomyoma)
- GIST
- melanoma
- lymphoma
- small cell carcinoma
- metastasis
causes of gastric carcinoma
- environmental (smoking, low B12, hypochlorohydria)
- gastric polyp
- menetrier’s disease
- gastric stump
- h. pylori
- EBV-related
- gastric peptic ulcer
- genetic (HNPCC, APC, Li Fraumeni, HDGC)
gastric carcinoma and h.pylori
- nitrate reduction generates mutagenic niroso
- polymorph activation generates ROM and NO which results in DNA damage. repair is enhanced by ascorbic acid, the secretion of which into gastric juice is decreased by h pylori
- increased cell turnover, important for carcinogenesis
why is Her2 staining important in gastric tumours?
they can test positive for the receptor, which indicates that they can respond to trastuzumab
other types of tumours that can occur in the stomach
- smooth muscle tumours
- lymphoma
- carcinoid
- GIST
associations to GI lymphomas
- H.pylori gastritis
- mediterranean region
- refractory sprue
- congenital immunodeficiencies
- HIV
associations to sprue
- EATCL in long standing sprue
- younger age group
- poor prognosis
features of mediterranean lymphoma
- IPSID
- Plasma cell diff. with synthesis of IgA heavy chain
- Malabsorption often precedes lymphoma
- May regress after antibiotic therapy (Campylobacter
jejuni?)
where is it most common to have SI adenoma?
- ampulla
- jejunum
- ileum
risk factors for SI adenoma
- FAP
- cystic fibrosis
- Crohn’s
- coeliac
- PJ syndrome and juvenile polyposis
- long standing ileostomies
where, in the GIT, can carcinoid tumours happen?
- appendix
- SI
- rectum
- stomach
- colon
what are colonic polyps?
an abnormal growth of tissue projecting from the colonic mucosa
what is the most common precursor of colon cancer?
adenomas
types of epithelial colonic polyps
- neoplastic: serrated, adenomatous
- hamartomatous: juvenile, peutz-jeghers (both cause polyposis)
- polyposis syndromes: FAP, Gardner’s, serrated polyposis
what are pedunculated polyps?
polyps with stalks
how do pedunculated polyps arise?
as the sessile polyp enlarges, the adjacent cells proliferate and there is traction on the luminal protrusion, creating the stalk
causes of hamartomatous polyps
- sporadic
- components of various genetically determined or acquired syndromes
- can be associated with pre-malignant or neoplastic lesions
what are juvenile polyps?
focal malformations of the epithelium and lamina propria
types of juvenile polyps
- sporadic
- syndromic
presentation of juvenile polyps
rectal bleeding
what can these juvenile polyps cause?
- intussusception
- intestinal obstruction
- polyp prolapse through the anal sphincter
what is another name for retention polyps?
sporadic juvenile polyps
extraintestinal manifestation of juvenile polyposis
- pulmonary arteriovenous malformation
- congenital manifestations
what is Peutz-Jeghers syndrome?
rare autosomal dominant syndrome presents at a median age of 11 years with multiple GI hamartomatous polyps and mucocutaneous hyperpigmentation (dark blue to brown)
what can lesions of Peutz-Jeghers syndrome cause?
intersussception
clinical features of Peutz-Jeghers syndrome
- multiple polyps in th SI
- mucocutaneous hyperpigmentation
- positive family history
how do inflammatory polyps present?
solitary rectal ulcer syndrome
clinical features of inflammatory polyps
- rectal bleeding
- mucus discharge
- inflammatory lesion of the anterior rectal wall
underlying cause of inflammatory polyps
impaired relaxation of the anorectal
sphincter that creates a sharp angle at the anterior rectal shelf and leads to recurrent abrasion
and ulceration of the overlying rectal mucosa
how can the mucosa prolapse in scenarios of inflammatory polpys
the polyps can get trapped in the faecal stream leading to mucosal prolapse
histological features of inflammatory polyps
- mixed infiltratory infiltrates
- erosion
- epithelial hyperplasia
- lamina propria fibromuscular hyperplasia
what are adenomatous polyps?
True neoplastic polyps formed by excessive growth of the colorectal epithelium; divided by
the morphology of the glandular tissue into tubular, tubulovillous, and villous types.
causes of adenomatous polyps
- sporadic (mainly)
- hereditary syndromes
risk factors of adenomatous polyps
- family history of colorectal adenocarcinoma