Colon pathology Flashcards
what is a polyp
a tumour (swelling) protrusion above an epithelial surface
what are the differential diagnosis’s of colonic polyps
- adenoma
- serrated polyp
- polypoid carcinoma
- other
what are the two types of polyp
epithelial
mesenchymal
what are the diff types (2) and examples of epithelial polyp
benign: neoplastic (adenoma) inflammatory hamartomatous metaplastic
malignant:
polypoid (adenocarcinomas)
carcinoid polyps
adenoma of colon….
benign and non-invasive, do not metastasise
all _____ are dysplastic
adenomas
what is the progression from benign to malignant
normal mucosa -> adenoma (dysplastic) -> adenocarcinoma (invasive)
why must all adenomas be removed and how it is done
because they are all premalignant
endoscopically or surgically
how is adenocarcinoma treated
colon/rectum is removed and sent to pathology for staging
how is colorectal carcinoma staged?
dukes staging and TNM staging predicts prognosis
confined by muscularis propria
dukes A (T1 or T2, N0)
through muscular propria
dukes B (T3 or T4, N0)
metastatic to lymph nodes
Duke C (any T, N1 or N2)
left sided colorectal carcinoma makes up __% of tract and what structures does this include
75%
rectum, sigmoid and descending
right sided colorectal carcinoma makes up ___% of tract including ___ and ____
25%
caecum and ascending
p/c of left sided colorectal carcinoma
blood PR, altered bowel habit, obstruction
p/c right sided
anaemia, weight loss
what are the varied gross appearances of colorectal carcinoma
polypoid, structuring, ulcerating
what is the pattern of spread of local invasion colorectal cancers
mesorectum, peritoneum, other organs
what is the lymphatic spread of cancers
mesenteric nodes
what is the haematogenous spread of carcinomas
liver, distant sites
what are the two inherited cancer syndromes
hereditary: non polyposis, Coli (HNPCC) - <100 polyps
familial - adenomatous, polyposis (FAP) - >100 polyps
difference between HNPCC and FAP
HNPCC: late onset autosomal dominant defect in DNA mismatch repair inherited mutation in MLH-1, MSH-2, PMS-1 or MSH-6 genes right sided tumours <100 polyps mucinous tumours crowns like inflammatory response assoc with gastric and endometrial carcinoma
FAP: early onset autosomal dominant defect in tumour suppression inherited mutation in FAP gene throughout colon > 100 polyps adenocarcinoma NOS no specific inflammatory response assoc with Desmoid tumours and thyroid carcinoma
