Primary tumours of the small bowel are rare clinicalentities and almost 80% of them are malignant.(2) In the USA, incidence isreported between 0.
3–2.0 cases per100,000 cases, with a greater prevalence among the black community.3, 4.Unsubstantialdata’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 %) 5The commonest location of small bowel adenocarcinoma(SBA) is in the duodenum (57 %), jejunum (29%) and ileum (10%) 6. The knownclinical manifestation of small-bowel tumours is abdominal pain,gastrointestinal (GI) bleeding and GI obstruction (7) In view of nonspecificclinical signs and symptoms, absence of good screening methods and thedifficulty in performing small bowel examination causes the delay in detectionof SBA.(1) Case Presentation We present a 31 year old male patient with underlyingGouty Arthritis who for the past 2 years experiencing intermittent epigastricand left upper quadrant (LUQ) pain associated with anaemia and constipation.Patient’s mother is diagnosed with cervical cancer and currently undergoingtreatment.
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 (polypectomydone, HPE: tubulovillous adenoma with moderate grade dysplasia) and ceacal(polypectomy done, HPE: tubulovillous adenoma with low grade dysplasia), BMATshowed IDA with no evidence of haematological disorders. Due to workcommitments and frequent travelling, patient did not comply with regular followup. A year later his anaemic symptoms worsens and was warded in our hospitalfor syncopal attack secondary to anaemia.
Patient claims still having intermittent LUQ pain,constipation, loss of appetite and loss of weight. He denied any noticeableblack tarry stool or per rectal bleeding.Physical examination revealed an ill-defined large palpableabdominal mass over left upper quadrant. Laboratory tests showed anaemia withhaemoglobin count of 6.
7g/dL with leukocytosis, Full blood picture shows IronDeficiency Anaemia (IDA), Haemoglobin Analysis was normal and low level ofserum ferritin. Investigations of tumour-associated antigens showed normallevels of carcinoma-embryonic antigen (CEA) of 0.5ng/ml .Repeated OGDS andcolonoscopy in HUSM were conclude normal. Abdominal computed tomography (CT)scans demonstrate aneurysmal dilatation of the jejunum with enhancing jejunalwall thickening 8.3cm x 8.8cm x 12.4cm.
Multiple enlarged node adjacent tomass.Left lung reticular change likely represents infection. (Fig. 1) CT guidedbiopsy of the mass was done, revealing moderately differentiatedadenocarcinoma. Subsequently patient underwent exploratory laparotomy, smallbowel tumour resection and primary side to side anastomosis.
Intraoperativelynoted 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 wrappedby greater omentum. Multiple large feeding vessels supplying thetumour.Carefull inspection did not show any evidence of metastatic lesions inthe peritoneum or liver.
Pathologic examination, HPE reveals moderatelydifferentiated adenocarcinoma with infiltration to one out of sixteen resectedlymph nodes with clear surgical margin archieved.Synaptophysun and ChromograninA is negative. Pathological staging was T4N1Mx, Stage 3a.Patient postassessment by oncology team, was decided for adjuvant chemotherapy with Xeloxfor a total of 8cycles. Patient was doing well during last follow up. Discussion SBA is the one of the rarest of the gastrointestinalmalignancies (5% of all GI malignancies).SBA has higher incidence in men (0.
80per 100,000) than women (0.55), prevalent between age group 55–65, incidenceincreasing after age 40. (1, 8) Lesser contact exposure to carcinogen and lowerbacterial concentration count is directly attributed to shorter transit time offood bolus in the small bowel. Furthermore, elevated levels of IgA and the highstress tolerance nature of the small bowel are believed to contribute to thelow tumour incidence (9).Adenocarcinomas comprise 30-40% of all primarymalignant small intestinal neoplasms, followed by carcinoid tumours (15-20%),lymphomas (15-20%), and sarcomas (10–15%) (5) Adenocarcinoma is commonly foundin the duodenum and proximal part of the jejunum, where else in the ileum,lymphoma and carcinoid tumours are prevalent. Sarcoma can be found anywhere inthe small bowel.
Hemangiomas, gastrointestinal stromal tumours, adenomas, andhamartomas comprise benign small bowel tumours. Due to presence of the ampulla of Vater leading tohigher concentration of bile and its metabolites in the duadenum and proximaljejunum ,is postulated for higher occurence of SBA in that area.(13,14,15)Exact pathogenesis of SBA still remains unknown. Onethird of pre-existing solitary small bowel adenoma is conjectured to transforminto invasive carcinoma.(12) SBA is believed to have association with certaingenetic conditions such as Peutz-Jeghers , hereditary nonpolyposis colon cancer, and familial adenomatous polyposis.(10) Other major ethological factors arechronic inflammation of the small intestine like Crohn’s disease and celiacdisease.
(11)In our case study, contrary to the norm, SBA is foundin a 31 year young man. Initial symptoms were vague non-specific abdominal painwith anaemia and the mass remained undetectable until much later. Thiscorresponds to study by Debaja BS et al; Diagnosis of SBA is made at advancedstages, that is about 40% of patient at the time of diagnosis of SBA is madewould be in stage 3 ( presence of lymph node metastasis) and stage 4 (distancemetastasis).(1,16) The known clinical manifestation of small-boweltumours is nonspecific abdominal pain, GI bleeding (24%), GI obstruction (40%),nausea/vomiting and loss of weight, in which our patient had evidence of occultblood loss, LUQ abdominal pain and loss of weight.(7,17)Carcinoembryonic antigen (CEA) and Ca19.9 are neithersensitive nor specific in cases of small bowel carcinoma so plas minimal roleis establising the diagnosis of SBA.
CEA and Ca19.9 is found to be elevated in 30% and 41% respectively in metastatic disease (21) In ourpatient both CEA and Cac19.9 is within normal rage.In cases of diagnosed SBAwith elavated values of CEA and/or Ca19.9, these markers can serve as surveillanceand assessment tool in post surgical resection patient and to monitor diseaseprogression.
(22)Oesophagogastroduodenoscopy andcolonoscopy is not helpful in detection of SBA unless the lesions is situated in close proximity of the duodenum or terminalileum. Neverthelessmandatory to exclude other concurrent pathologies. Overall accuracy rate of CT scan is only about 47% indetection of clinically non palpable small bowel lesions but CT provides additional informationabout the regional nodal involvement, extra mucosal infiltration and distantmetastases. PET/CT is far superior in detection of small or flat intestinalmucosa lesions and aids to differentiate malignant lesions from benign onesbased on the uptake of 18f-FDG. (1, 18) Magnetic resonance imaging (MRI) is gaining popularityto assess bowel periatalsis and to provide images with higher reosolution withnegation of ionizing radiation.
Pitfalls include MRI availibity and assessabiltyfor usage in acute settings and also the cost involved.Newermodalities available to investigate the small bowel include video capsuleendoscopy(VCE), device assisted enteroscopy (DAE),cmagnetic resonanceenteroclysis/enterography (MRE). In cases with occult GI bleeding,iron deficiency anemia, non specific abdominal pain and others, there is a probabilityof 4% in detection of SBA with VCE.Concurrent and complementary usage of DAEand MRE with VCE can incease the diagnosis yield.However there is a small riskof capsule retention is patient with impending GI obstruction with the usage ofVCE.(19)