Primary Analysis was normal and low level of

Primary tumours of the small bowel are rare clinical
entities and almost 80% of them are malignant.(2) In the USA, incidence is
reported  between 0.3–2.0 cases per
100,000 cases, with a greater prevalence among the black community.3, 4.Unsubstantial
data’s are available for Asian population.

Quotidian histological types of small bowel neoplasms:
adenocarcinoma comprises (30–40 %), followed by carcinoid tumour (35–42 %),
lymphoma (15–20 %), and sarcoma (10–15 %) 5

The commonest location of small bowel adenocarcinoma
(SBA) is in the duodenum (57 %), jejunum (29%) and ileum (10%) 6. The known
clinical manifestation of small-bowel tumours is abdominal pain,
gastrointestinal (GI) bleeding and GI obstruction (7) In view of nonspecific
clinical signs and symptoms, absence of good screening methods and the
difficulty in performing small bowel examination causes the delay in detection
of SBA.(1)

 

 

Case Presentation

 

We present a 31 year old male patient with underlying
Gouty Arthritis who for the past 2 years experiencing intermittent epigastric
and left upper quadrant (LUQ) pain associated with anaemia and constipation.
Patient’s mother is diagnosed with cervical cancer and currently undergoing
treatment. About 1 year ago patient sought treatment at local government hospital.
Initial assessment did not yield any significant findings.Ogds was normal,
colonoscopy revealed multiple colonic polyp over hepatic flexure (polypectomy
done, HPE: tubulovillous adenoma with moderate grade dysplasia) and ceacal
(polypectomy done, HPE: tubulovillous adenoma with low grade dysplasia), BMAT
showed IDA with no evidence of haematological disorders. Due to work
commitments and frequent travelling, patient did not comply with regular follow
up. A year later his anaemic symptoms worsens and was warded in our hospital
for syncopal attack secondary to anaemia.

Patient claims still having intermittent LUQ pain,
constipation, loss of appetite and loss of weight. He denied any noticeable
black tarry stool or per rectal bleeding.

Physical examination revealed an ill-defined large palpable
abdominal mass over left upper quadrant. Laboratory tests showed anaemia with
haemoglobin count of 6.7g/dL with leukocytosis, Full blood picture shows Iron
Deficiency Anaemia (IDA), Haemoglobin Analysis was normal and low level of
serum ferritin. Investigations of tumour-associated antigens showed normal
levels of carcinoma-embryonic antigen (CEA) of 0.5ng/ml .Repeated OGDS and
colonoscopy in HUSM were conclude normal. Abdominal computed tomography (CT)
scans demonstrate aneurysmal dilatation of the jejunum with enhancing jejunal
wall thickening 8.3cm x 8.8cm x 12.4cm.Multiple enlarged node adjacent to
mass.Left lung reticular change likely represents infection. (Fig. 1)

 CT guided
biopsy of the mass was done, revealing moderately differentiated
adenocarcinoma. Subsequently patient underwent exploratory laparotomy, small
bowel tumour resection and primary side to side anastomosis. Intraoperatively
noted small bowel tumour measuring 20x 20cm (50 cm from the ligament of Treitz,
DJ junction). The mass was adhered to anterior abdominal wall, and was wrapped
by greater omentum. Multiple large feeding vessels supplying the
tumour.Carefull inspection did not show any evidence of metastatic lesions in
the peritoneum or liver. Pathologic examination, HPE reveals moderately
differentiated adenocarcinoma with infiltration to one out of sixteen resected
lymph nodes with clear surgical margin archieved.Synaptophysun and Chromogranin
A is negative. Pathological staging was T4N1Mx, Stage 3a.Patient post
assessment by oncology team, was decided for adjuvant chemotherapy with Xelox
for a total of 8cycles. Patient was doing well during last follow up.

 

 

Discussion

 

SBA is the one of the rarest of the gastrointestinal
malignancies (5% of all GI malignancies).SBA has higher incidence in men (0.80
per 100,000) than women (0.55), prevalent between age group 55–65, incidence
increasing after age 40. (1, 8) Lesser contact exposure to carcinogen and lower
bacterial concentration count is directly attributed to shorter transit time of
food bolus in the small bowel. Furthermore, elevated levels of IgA and the high
stress tolerance nature of the small bowel are believed to contribute to the
low tumour incidence (9).

Adenocarcinomas comprise 30-40% of all primary
malignant small intestinal neoplasms, followed by carcinoid tumours (15-20%),
lymphomas (15-20%), and sarcomas (10–15%) (5) Adenocarcinoma is commonly found
in the duodenum and proximal part of the jejunum, where else in the ileum,
lymphoma and carcinoid tumours are prevalent. Sarcoma can be found anywhere in
the small bowel. Hemangiomas, gastrointestinal stromal tumours, adenomas, and
hamartomas comprise benign small bowel tumours. Due to presence of the ampulla of Vater leading to
higher concentration of bile and its metabolites in the duadenum and proximal
jejunum ,is postulated for higher occurence of SBA in that area.(13,14,15)

Exact pathogenesis of SBA still remains unknown. One
third of pre-existing solitary small bowel adenoma is conjectured to transform
into invasive carcinoma.(12) SBA is believed to have association with certain
genetic conditions such as Peutz-Jeghers , hereditary nonpolyposis colon cancer
, and familial adenomatous polyposis.(10) Other major ethological factors are
chronic inflammation of the small intestine like Crohn’s disease and celiac
disease.(11)

In our case study, contrary to the norm, SBA is found
in a 31 year young man. Initial symptoms were vague non-specific abdominal pain
with anaemia and the mass remained undetectable until much later. This
corresponds to study by Debaja BS et al; Diagnosis of SBA is made at advanced
stages, that is about 40% of patient at the time of diagnosis of SBA is made
would be in stage 3 ( presence of lymph node metastasis) and stage 4 (distance
metastasis).(1,16)  

The known clinical manifestation of small-bowel
tumours is nonspecific abdominal pain, GI bleeding (24%), GI obstruction (40%),
nausea/vomiting and loss of weight, in which our patient had evidence of occult
blood loss, LUQ abdominal pain and loss of weight.(7,17)

Carcinoembryonic antigen (CEA) and Ca19.9 are neither
sensitive nor specific in cases of small bowel carcinoma so plas minimal role
is establising the diagnosis of SBA. CEA and Ca19.9  is found to be elevated in 30% and 41%  respectively in metastatic disease (21) In our
patient both CEA and Cac19.9 is within normal rage.In cases of diagnosed SBA
with elavated values of CEA and/or Ca19.9, these markers can serve as surveillance
and assessment tool in post surgical resection patient and to monitor disease
progression.(22)

Oesophagogastroduodenoscopy and
colonoscopy is not helpful in detection of SBA unless the lesions is situated in close proximity of the duodenum or terminal
ileum. Nevertheless
mandatory to exclude other concurrent pathologies. Overall accuracy rate of CT scan is only about 47% in
detection of clinically non palpable small bowel lesions but CT provides additional information
about the regional nodal involvement, extra mucosal infiltration and distant
metastases. PET/CT is far superior in detection of small or flat intestinal
mucosa lesions and aids to differentiate malignant lesions from benign ones
based on the uptake of 18f-FDG. (1, 18)  Magnetic resonance imaging (MRI) is gaining popularity
to assess bowel periatalsis and to provide images with higher reosolution with
negation of ionizing radiation.Pitfalls include MRI availibity and assessabilty
for usage in acute settings and also the cost involved.

Newer
modalities available to investigate the small bowel include video capsule
endoscopy(VCE), device assisted enteroscopy (DAE),cmagnetic resonance
enteroclysis/enterography (MRE). In cases with occult GI bleeding,
iron deficiency anemia, non specific abdominal pain and others, there is a probability
of 4% in detection of SBA with VCE.Concurrent and complementary usage of DAE
and MRE with VCE can incease the diagnosis yield.However there is a small risk
of capsule retention is patient with impending GI obstruction with the usage of
VCE.(19)