Small Bowel Tumours

Benign
Lipoma
Leiomyoma
Adenoma

Malignant
Carcinoid tumours
Carcinoma
Lymphoma
Sarcoma (GI stromal tumours)


Carcinoid Tumours
Neuroendocrine cells
Secrete gastrin/5HT/somatostatin/VIP/Insulin/other endocrine things

Site
Malignancy depends on site of origin
Appendix/Rectum
Locally invasive
Resectable
SmI/St/Col
Highly invasive
Metastatic

NB - also occur in lungs

Symptoms and Cx - Carcinoid Syndrome
Flushing
Diarrhoea
Wheezing
Abdo fibrosis
Cardiac valve fibrosis/stenosis/regurgitation

If metastasises to liver:
5HT bypasses portal system = CS
 - otherwise metab in first past metabolism
NB therefore lung tumours drain directly into system = CS


Gastrointestinal Stromal Tumours
*Stomach/SmI
SmM/neural differentiation
Ben/Malig
Malignant = higher mitotic rate/necrosis/neural differentiation


Gastrointestinal Tract Lymphomas
*GIT extranodal lymphoma

1) MALT lymphoma
2) Enteropathy-associated lymphomas
3) Other B Cell lymphomas (mantle cell Lys & follicular Lys)

1) MALT
B Cell neoplasm
Fr mucosa associated lymphoid tissue
*SmI & Col - Tx difficult
St with H.Py
H.Py = chronic inflammation = chronic inflammatory cell infiltrate
Tx of H.Py can Tx Lymphoma (therefore ABs)

2) Enteropathy-associated Lymphomas
eg a/w/ Coeliac disease
* T cell