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Large bowel - Coggle Diagram
Large bowel
Tumours of the Large Bowel
Primary tumours
Non-neoplastic polyps
Epithelial neoplasms
Benign adenomatous polyps
Adenocarcinoma
Malignant
Carcinoid
Mesenchymal neoplasms
Lymphoma
Secondary tumours (rare)
Tumours of large bowel are more common than tumours of the small bowel
Polyps
Mass arising from the mucosal epithelium or from the submucosal connective tissue protruding into the lumen of the gut
There are Non-neoplastic polyps and Neoplastic polyps= Adenomas
non-neoplastic
Hyperplastic (metaplastic) polyps
Common lesions >50% of people over 60 years
Often found in the recto-sigmoid
Less than 5 mm
Single or multiple
Asymptomatic
Composed of non-neoplastic glands with goblet cell differentiation and serrated appearance
Results from delayed shedding of surface epithelial cells
Virtually no malignant potential
Hamartomatous polyps e.g. Juvenile, Peutz-Jeghers
Juvenile polyps
Hamartomatous malformations of bowel mucosa
Children < 5 years but can be encountered in adults
Rectum
Can be large (1-3 cm)
Cystically dilated glands in an inflamed stroma
No malignant potential
Peutz-Jegher polyps
Hamartomatous polyps of small intestine & colon
Single or multiple (Peutz-Jeghers syndrome): Glands and connective tissue with smooth muscle
Peutz-Jeghers syndrome
Autosomal dominant syndrome
Mucocutaneous pigmentation (around lips, oral mucosa, genitalia and palmar surfaces of the hand)
Multiple hamartomatous polyps throughout GI tract
No malignant potential but the patients have increased risk of developing GI and non-GI cancers (pancreas, breast, lung, ovary and uterus)
Hamartomatous syndromes
Cowden syndrome
Autosomal dominant syndrome (PTEN)
Multiple hamartomatous polyps and trichoepitheliomas. Trichoepithelioma is a rare benign skin lesion that originates from hair follicles. Trichoepitheliomas are mostly seen in the scalp, nose, forehead, and upper lip. These skin lesions originate from benign proliferation of epithelial-mesenchymal origin cells.
No malignant potential but the patients have increased risk of developing thyroid and breast cancer
Cronkhite-Canada syndrome: Hamartomatous polyps, nail atrophy, skin pigmentation
Inflammatory (pseudo) polyps
Inflamed regenerative mucosa surrounded by ulcerated tissue
Seen in patients with longstanding inflammatory bowel disease
Lymphoid polyps
Pedunculated (with a stalk) or sessile (flat)