GIT Neoplasms
Tumors of the small intestine
Unlike the large bowel the small intestine is
rarely the seat of tumors.
5% all GIT tumours
1-2 % malignant GIT tumours
Age >50 yr.
There are several theories to explain this fact;
1.
Rapid transit time decrease the time for contact of
carcinogens with the mucosa.
2.
The local immune system of the small bowel mucosa.
3.
The alkaline pH of the succus entericus.
4.
The absence of bacteria that might convert certain
ingested products to carcinogens.
5.
The presence of mucosal enzymes that destroy
certain carcinogens.
The symptoms that associated with small bowel
neoplasms are often vague & they include;
1.
2.
3.
4.
5.
Epigasteric discomfort.
Nausea.
Vomiting.
Abdominal pain, which is often intermittent &
colicky.
Diarrhea & bleeding.
Diagnosis by :
barium follow through study,
CT scan, endoscopy,
capsule, endoscopy,
20-25% preoperative diagnosis
In most of cases diagnosis occur at
explorative laparotomy
The most common indication for operation in patients with
neoplasms of small bowel are
obstruction, bleeding & pain.
Benign tumors
The most common lesions are
adenomas, liomyomas & lipomas,
other benign tumors include
hamartoma, fibromas,
angiomas, lymphangiomas,
Neurofibromas & hemangiomas.
A.
Benign tumours
more in distal part of small bowel:
1. Leiomyomas & GIST tumours
originated from interstial cells of Cajal
( mesodermal in origin )
compose 0f 70 % spindle cell &
30 % epithelial cells
The benign form of these tumours are 3-4 times more
common than malignant one
They express CD 117 in 90 % of cases &
CD 34 in 80 % of cases
Treatment: local resection.
2. adenomas:
3 types:True adenomas
Villous adenomas
Brunner adenomas
Treated by primary resection if they are causing symptoms
except for large villous adenomas which requires segmental
resection.
3. lipomas: treated by simple excision
4. Peutz Jegar ( hamartomas )
This is an inherited syndrome &
the mode of inheritance is by simple mendalian dominant.
seen more frequently in the jejunum & ileum
but the may affect whole the GIT
& also extra GIT organs like the ovary, lungs, breasts & uterus.
It consists of;

Familial intestinal hamartomatous polyposis where it
cause hemorrhage & often intussusception.

Melnosis of the oral mucous membrane & the lips.
Histology;
the polyps can be likened to trees & consist of smooth muscle
fibers & covered by normal mucosa.
Treatment ;
by segmental resection of severely involved segment only.
5. haemangiomas : they are multiple in 60% of cases but
most common site is the jejunum. In cases of bleeding
the treatment is by segmental resection.
B. malignant small bowel tumours:
1. adenocarcinoma 50%
2. carcinoid tuomur
3. malignant GIST 20%
4. lymphomas 7-25%
Adenocarcinoma
more in duodenum & jejunum,
and it usually late in diagnosis.
Occurring in carcinoma age group,
prognosis depends on the stage of disease.
Malignant GIST
more in jejunum & ileum
spread by direct invasion & by hematogenous way
to liver ,lungs & bone.
Prognosis depends on stage & grade of disease.
Lymphomas
more in ileum,
occurring at younger age group &
seen more in patients
with celiac disease & AIDS.
Treatment of adenocarcinoma & lymphoma
by:
1. wide local excision
if not possible.
2. palliative resection if not possible
3. bypass operations
Treatment of malignant GIST tumours
by
Segment a resection with wide margin
& if possible
resection of liver metastasis.
Chemotherapy & radiotherapy are of little role in
adenocarcinoma
but are helpful in lymphoma cases
and Imatinib is useful in malignant GIST.
Prognosis : > 50% had metastasis at laparotomy,
5 yrs survival is < 25%.
3- carcinoid tumor; (25%)
These tumors occur throughout the GIT
& also in the bronchus, testis & ovary.
The appendix is the commonest site involved
(65%)
followed by the ileum (25%).
These tumors arise in the cells of kulchitsky
at the base of the crypts of lieberkuhn,
when metastasis occurs to the liver the disease is called
carcinoid syndrome.
The tumor produces 5HT (serotonin)
which might be present as 5- hydroxt indol acetic acid
in the urine during the attacks.
Also it may produce
kinins, PGs, kallikrin,
substance P, neurotrophin ,
chromogranin A>90%, Hstamin & Dopamin.
The clinical syndrome consists of
reddish-blue cyanosis,
flushing attacks, diarrhea,
borborygmi, asthmatic attacks & eventually some times
pulmonary & tricuspid valves stenosis.
Classically the flushing attacks are induced by alcohol.
Diagnosis by :
estimation of 5HIAA in 24 hrs urine
chromogranin A
provocative test ( clinical test ) by giving patient
pentagasterin calcium, epinephrine.
Treatment;
Tumor < 1 cm ------ local resection
When small lesions discovered at appendectomy, removal of the appendix is the
sufficient treatment.
Tumors > 1cm & bigger + LNs involvement ------ wide resection
Eg : terminal ileum ---- Rt hemicolectomy
Liver secondaries are Treated accordingly :
Segmentectomy or lobectomy s.t liver transplantation ??
+
medical treatment
by somatostatin ( Octeriotide ) + antihistamins &
alpha methyldopa & steroids . might help to reduce the severity of the attacks.
Prognosis :
most better than other small intestinal malignancies
Small tumors has 100% 5 years survival rate
Regional disease 65%
5years survival rate
Distant metastasis 25 – 35 % 5 years
survival rate
Metastatic neoplasm :
is the most common small bowel tumor reaching them from
direct extension or
by implantation or
from extra-abdominal tumors;
lungs, breast,
& more common from melanoma.
Treatment:
local resection or bypass to relieve obstruction.