Small Bowel Tumours

Small Bowel Tumours

·        Benign: Polyps (Peutz-Jeghers), Juvenile Polyps, Adenomas, Stromal tumours

·        Malignant:

o  Carcinoid tumours:

§  Tumours arising from neuroendocrine cells

§  Mainly midgut. Similar tumours occur in lungs, ovaries, biliary tree 

§  Macroscopic appearance: submucosal elevations, yellow/grey, infiltrative, ulceration, multiple 

§  Microscopic appearance: Uniform cells, oval nucleus, fine chromatin, pink cytoplasm, neuroendocrine granules

§  Clinical: malignancy depends on site.  Appendix and rectum better, ileal and colonic worse 

§  Carcinoid Syndrome: due to excess serotonin. Occurs with hepatic metastases (liver efficiently removes 5HT from portal circulation) ® wheezing, right sided heart failure, diarrhoea (­motility), abdominal pain, oedema, skin lesions

o  Lymphomas of the GI tract

§  Affects stomach, ileum, colon, jejunum.  Arise in the gut, or spread there from elsewhere

§  3 types: MALT, Sprue associated, and immunoproliferative small intestinal disease 

§  Macroscopic appearance: plaque-like expansion of the mucosa ® ulcerating, fungating mass, can ® obstruction or perforation 

§  Microscopic appearance: tumour cells diffusely infiltrate the wall, cytologically resemble follicular lymphoma cells

§  Clinical outcome: prognosis depends on depth of invasion, size, direct extension

o  Adenocarcinoma: Uncommon.  Resembles those in the colon