DOUBLE-BALLOON ENTEROSCOPY IN THE DIAGNOSIS OF AN ADENOCARCINOMA OF THE FOURTH PORTION OF THE DUODENUM : REPORT OF A CASE

Primary adenocarcinoma of the duodenum is a rare condition representing around 0.5% of all gastrointestinal tract cancers. 1-5 Adenocarcinomas are the most common histological type of malignant neoplasms of the duodenum accounting for 50% of the cases, followed by carcinoid, leiomyosarcomas and lymphomas. 4,6-8 Adenocarcinoma of the duodenum usually occurs between the sixth and seventh decades, and equal sex distribution is reported in the majority of the studied series. The second duodenal portion has the highest incidence of adenocarcinoma representing 74% of the cases, followed by third (13%), fourth (9%) and first (4%) portions. The diagnosis of this disease is often delayed because symptoms and signs are nonspecific and vague, similar to those found in many benign conditions. In cases comprehending the third and fourth portions of the duodenum, the diagnosis may be even more delayed because endoscopic examination of the distal duodenum is poorly accomplished. We report a case of a 41-year-old man with primary adenocarcinoma of the fourth portion of the duodenum who presented with anemia and abdominal pain. His final diagnosis was confirmed with histological examination of biopsies performed through double-balloon enteroscopy (DBE).


INTRODUCTION
][8] Adenocarcinoma of the duodenum usually occurs between the sixth and seventh decades, [4][5][6] and equal sex distribution is reported in the majority of the studied series. 3,4he second duodenal portion has the highest incidence of adenocarcinoma representing 74% of the cases, followed by third (13%), fourth (9%) and first (4%) portions. 4he diagnosis of this disease is often delayed because symptoms and signs are nonspecific and vague, similar to those found in many benign conditions. 3,5,7,9In cases comprehending the third and fourth portions of the duodenum, the diagnosis may be even more delayed because endoscopic examination of the distal duodenum is poorly accomplished. 9,10e report a case of a 41-year-old man with primary adenocarcinoma of the fourth portion of the duodenum who presented with anemia and abdominal pain.His final diagnosis was confirmed with histological examination of biopsies performed through double-balloon enteroscopy (DBE).

CASE REPORT
A 41-year-old man was admitted to our hospital with a 3-month history of anemia.At entry, full blood count results showed hemoglobin of 6.8 g/dl and hematocrit of 22%.This patient reported a weight loss of 40kg over the previous four years, but no further investigation, such as abdominal CT or Barium meal radiography, was done before, due to a coincident bariatric jejunum-ileal bypass surgery at that time.
Upper gastrointestinal endoscopy showed antral erythematous gastritis, and no alteration was noted in the first or second portions of the duodenum.Fecal stool occult blood testing was positive (3+), but colonoscopy showed no alterations.Scintigraphy with 99 Tc and marked erythrocytes was performed and revealed positivity for intestinal bleeding, probably at the proximal small bowel.
DBE demonstrated first, second and third portions of the duodenum with no abnormalities.In the fourth portion of the duodenum a vegetative, infiltrative and friable lesion was noted, extending about 10 cm, involving almost all the circumference and the lumen of the organ, allowing however the transposition of the double-balloon enteroscope.Multiple biopsies were performed.Histological examination demonstrated moderately differentiated adenocarcinoma of the duodenum.The immunohistochemical evaluation was consistent with adenocarcinoma.After the diagnosis, the patient and his family elected treatment at a private hospital and we lost the follow-up.

DISCUSSION
Primary adenocarcinoma of the duodenum, excluding that of the ampulla of Vater is a rare condition that was first described in 1746 by Hamburgur. 7Duodenal adenocarcinoma arises in most of cases from the Lieberkühn epithelium of the duodenal mucosa. 9Various etiological and risk factors, such as familial adenomatous polyposis, Gardner's and Turcot's syndrome, Crohn's disease, celiac disease, polypoid lesions, Lynch's syndrome are related to duodenal adenocarcinoma. 7,8,10However, in this case the patient did not have any of the associated conditions.
The extreme rarity and the vagueness of presenting symptoms makes it hard to diagnose this tumor.The most fre- quent signs and symptoms found in patients with adenocarcinoma of the duodenum are abdominal pain, weight loss, nausea, anemia, and vomiting. 3,4,7In this patient, anemia and weight loss were present.This case raises an issue about the follow-up after bariatric surgery, since not all the symptoms might be correlated to the surgical procedure.Intensive care and meticulous diagnostic procedures after application of this technique should be the first priority.
Diagnostic methods may include x-ray films, abdominal CT, and more recently capsule endoscopy and DBE.][10] CT is valuable for visualizing and staging the tumor. 8Conventional endoscopy may diagnose proximal tumors but is inadequate for distal duodenal tumors. 9BE was described by Yamamoto et al., in 2001, and the system consists of an enteroscope, an overtube and a balloon pump controller. 11The double-balloon enteroscope has two balloons, one attached to the tip of the endoscope and another at the distal end of an overtube that facilitates the progression of the endoscope through the small bowel.Loops can be easily reduced by gentle withdrawal of the endoscope while the balloons are inflated.With this technique, the endoscope can be advanced by pushing it through the overtube allowing endoscopic visualization of the entire small bowel, biopsies and therapeutic intervention. 12he affected site of the duodenal portion is relevant (D1, D2, D3 and D4) for treatment and prognosis.D1 and D2 tumors should be treated with pancreatic-duodenal resection (PDR) and D3 and D4 tumors should be treated with local resections.A palliative bypass can be performed in non-resectable tumors with obstructive symptoms. 1,2,4,7hemotherapy in the treatment of duodenal adenocarcinoma is not associated with good results and more studies are required on this subject. 4Some authors have reported a different prognosis based on the site of the tumor, which showed a better survival rate in the D3 and D4 forms. 9In fact, while the 5-year survival for all duodenal carcinomas ranges from 17% to 25%, a review of the series confined to D3 and D4 reveals a 5-year survival of approximately 75%. 10 The different prognosis of proximal and distal tumors should be attributed to embryological factors.Although different embryological origins for the duodenal sections are not universally accepted, some authors describe D1 and D2 as arising from anterior intestine and D3, D4 from the middle intestine. 7Carcinomas arising in the anterior intestine have a more aggressive behavior.Moreover PDR usually performed in D1 and D2 resectable tumors also contributes to the lower survival rate, since it has higher morbidity and mortality. 10 DBE is a safe and easily conducted method which permits full visualization of small bowel by using the oral or the anal route. 13For sedation, a combination of fentanyl, midazolam and propofol seems to be the best option.However, it is a time consuming procedure that has to be performed by two physicians; one controlling the overtube and the other managing the endoscope.
Prospective trials should be done in the near future to compare the efficacy of DBE versus capsule endoscopy regarding the diagnosis of small bowel disorders, in spite of the fact that endoscopic therapy is only achieved with DBE.
Therefore, in this case report, the usefulness of DBE was demonstrated.Through this technique, biopsies could be done to allow the histological examination of the lesion.Additionally, this case illustrates the need of close followup in bariatric surgery, as these patients may present with other diseases, such as neoplasias of the gastrointestinal tract, and hence the diagnosis may be delayed.It is noteworthy that these patients should be followed very closely, specially if they develop new symptoms.

Figure 1 .
Figure 1.Vegetative lesion on the fourth portion of the duodenum