Pathology of Colorectal Carcinoma Flashcards
what is a polyp
a protrusion above an epithelial surface
a tumour - does not indicate benign or malignant
differential diagnosis of polyp
adenoma
serrated poylp
polypoid carcinoma
other
macroscopic appearance of polyps
pedunculate sessile flat irregular surface long stalk
describe adenoma of colon
benign tumour - not invasive, does not metastasise
common
dysplastic
can develop to adenocarcinoma (malignant)
microscopic changes of adenoma of colon
tubullovillous
tubular
villous
treatment of adenomas
must be removed as they are always premalignant
via endoscopically or surgically
molecular genetic origins of colorectal adenomas
do not all have the same molecular genetic origins - separate pathways for inherited tumours and serrated adenomas
treatment of adenocarcinoma
surgery
microscopic changes in adenocarcinoma
tumour invades muscularis propria
moderately differentiated
staging of colorectal carcinoma
dukes staging - predicts prognosis
Dukes staging A
confined by muscularis proprietary
Dukes staging B
throughout muscularis propria
Dukes staging C
metastatic to lymph nodes
left sided colorectal carcinoma
includes the rectum, sigmoid and descending colon
symptoms and signs of left sided colorectal carcinoma
hypertension
altered bowel habits
obstruction
right sided colorectal carcinoma
includes the caecum and ascending colon
symptoms and signs of right sided colorectal carcinoma
anaemia
weight loss
pathology of colorectal carcinoma
varied gross appearance - polyploid, structuring, ulcerating
typical histopathological appearance
patterns of spread of colorectal carcinoma
local invasion
lymphatic spread
haematogenous
local invasion of colorectal carcinoma
mesorectum
peritoneum
other organs
lymphatic spread of colorectal carcinoma
mesenteric nodes
inherited cancer syndromes
hereditary non polyposis coli
familial adenomatous polyposis
describe hereditary non polyposis coli
late onset
autosomal dominant - defect in DNA mismatch repair
mutation in hereditary non polyposis coli
MLH-1, MSH-2, PMS-1 or MSH-6 genes
describe familial adenomatous polyposis
early onset
autosomal dominant - defect in tumour suppression
mutation in familial adenomatous polyposis
FAP gene
tumours of hereditary non polyposis coli
right sided < 100 polyps mucinous tumours Crohn’s like Inflammatory response Associated with gastric and endometrial carcinoma
tumours of familial adenomatous polyposis
throughout colon >100 polyps Adenocarcinoma NOS No specific inflammatory response Associated with desmoid tumours and thyroid carcinoma
