Carcinoma of the Colon, Rectum & Anus

Question 1

Aetiology, morphology and pathological consequences of large bowel carcinoma

Answer 1

Mostly sporadic, few due to chronic colitis or family syndromes. Age is biggest risk factor.
Most are adenocarcinomas that develop from polyps
Spread is through direct invasion through the bowel wall with later invasion of blood vessels and lymphatics that common metastases to liver and lung.

Question 2

Common symptoms suggestive of carcinoma of the colon, rectum and anus.

Answer 2

Rectal bleeding, stenosis - constipation, altered bowel habits, colicky pain. Iron def anaemia. Palpable mass? Palpable liver (mets?)

Question 3

Outline the staging system and relate this to possible findings on examination

Answer 3

TNM staging 
T1 (Mucosa) 2 (Muscularis Propria) 3 (Subserosa) 4 (Adjacent Organs) N1 (1-3 nodes) N2 (>4 nodes) 
Stage 0 - Confined to mucosa 
Stage 1 - T1 or T2 + N0 + M0 
Stage 2 - T3 or T4 + N0 + M0
Stage 3a - T1 or T2 + N1 
Stage 3b - T3 or T4 + N1 
Stage 3c - Any T + N2 
Stage 4 - Any T + Any N + M