Small bowel tumours

Question 1

Where are most small bowel tumours?

Answer 1

• Duodenum
• Can be benign or malignant
• They are rare

Question 2

Benign tumours of small bowel

Answer 2

• Adenomas - simple villous or tubular
• Brunners gland adenomas
• Less common - leiomyoma, lipomas, desmoid tumours

Question 3

Malignant tumour

Answer 3

• Adenocarcioma
• Neuroendocrine tumour
• Less common: stromal, sarcoma, lymphomas

Question 4

Pathophys of small bowel tumours

Answer 4

• Arise from pre-existing adenomas
• Accumulation of genetic abnormalities over several years
• Tumour supressor gene p53 and oncogene KRAS implicated in over 50% of SB adenocarcinomas

Question 5

Non-modifiable RF for SB adenocarcinoma

Answer 5

• Increasing age
• Crohns
• Coeliac disease
• Genetic conditions eg Peutz Jeghers, Lynch, Familial Adenomatous Polyposis

Question 6

Modifiable RF for adenocarcinoma

Answer 6

• Smoking
• Obesity
• Low fibre intake
• High intake red meats
• Alcohol excess

Question 7

Symptoms of SBT

Answer 7

• Asymptomatic initially
• As they increase in size –> SB obstruction due to luminal narrowing
• Less commonly - PR bleeding either as fresh or melena

Question 8

Examination findings for SBT

Answer 8

• Abdominal mass
• If metastatic - cachexia, hepatomegaly, jaundice, ascites
• Neuroendocrine can present with carcinoid syndrome

Question 9

Bedside and bloods for ?SBT

Answer 9

Massess not usually diagnosed pre op due to absence of symptoms but:
* High CEA - associated with adenocarcinoma in presence of liver mets
* High serum 5-hydroxyindole acetic acid (5-HIAA) observed in patients with carcinoid syndrome

Question 10

Imaging for ?SBT

Answer 10

• If proximal duodenum - OGD
• If endoscopy cannot reach - MRI enterography
• Can also use endoscopic US (esp if ampullary) or capsule endoscopy
• PET-CT then done for metastatic checks

Question 11

What imaging is usually actually done for SBT?

Answer 11

• As they present with ?SB obstruction a CT is usually done

Question 12

Management options for benign small bowel tumours

Answer 12

• If symptomatic - resection
• Either endoscopically or surgical resection - depends on patient factors, size and location
• Neoadjuvant chemotherapy or chemoradiotherapy may be needed for some locally advanced disease prior to surgery

Question 13

Treatment for local small bowel adenocarcinoma

Answer 13

• Surgical resection only definitive treatment
• Type of resection depends on location
• Segmental resection of small bowel often surgery done
• BUT duodenal tumours sometimes may need pancreaticoduodenectomy (Whipples) or segmental duodenal resection

Question 14

When is adjuvant chemotherapy used in small bowel adenocarcinoma?

Answer 14

If lymph node positive

Question 15

Treatment of metastatic small bowel cancer

Answer 15

• Chemotherapy
• Guided by patient factors, function
• Options inc fluoropyrimidine-based chemo, taxane based chemo or checkpoint inhibitors