Adenocarcinoma is the most common primary malignant neoplasm of the duodenum. It represents 0.3% of all gastrointestinal malignancies. It accounts for 50-70% of small bowel adenocarcinomas occurring either in the duodenum or proximal jejunum.
The peak prevalence is in the 7th decade. More than 50% of them having metastases at the time of diagnosis.
Most of the clinical features are non-specific which include upper abdominal pain and weight loss as the most common presenting symptoms, in the late phases of the disease a variety of symptoms and signs have been reported, like symptoms of proximal intestinal obstruction and jaundice, haematemesis, melaena, and occult blood in the stool. A variety of other findings, such as low back pain and alteration in bowel habit, have also been described.
Grossly they have napkin ring appearance or polypoidal fungatining mass. Patients with familial adenomatous polyposis and Gardner syndrome are considered to have a higher likelyhood of developing duodenal cancer. Patients who have duodenal polyps without a predisposing family history are also at an increased risk.
According to some publications, upper GI series seem to be the most accurate diagnostic modalities for small-bowel carcinomas. Upper GI shows features of mucosal pattern distortion, obliteration and narrowing. Delayed images may show hold up of barium at the site of the lesion.
The lesions appear as irregularly hypoechoic masses. Ultrasonography can diagnose and assess vascularity of larger lesions but the smaller tumours (<2 cm) may not be detected.
Treatment and prognosis
Duodenal adenocarcinoma is associated with a delayed diagnosis and poor prognostic and survival outcomes due to non specific clinical presentation.
Metastasis, poor tumour differentiation, increased depth of spread and pre-existing Crohn's disease are associated with poor prognosis.
Recurrence of the tumour is also a common entity. The most common sites of recurrence are the liver, lungs and peritoneum.
The only way to improve results is early diagnosis of primary tumour, by providing a higher resectability.
Pancreaticoduodenectomy is required for tumours of the first and second portion of the duodenum. In tumours of distal duodenum, segmental resection may be adequate.
Primary malignant tumors of the duodenum represent 0.3% of all gastro-intestinal tract tumors but up to 50% of small bowel malignancies. Primary malignant tumors of the duodenum must be differentiated from malignant tumors of the ampulla, pancreas and common bile duct. The most frequent tumor of the duodenum is adenocarcinoma . Other primary tumors are lymphomas, leiomyosarcomas, carcinoid tumors, gastrinomas, stromal tumors. Adenocarcinoma of the duodenum may arise from duodenal polyps observed in familial polyposis or Gardener's syndrome, or be associated with celiac disease . The tumor can be located in any part of the duodenum but the most frequent location is the second part.
Malignant tumors of the duodenum are observed with the same frequency in men and women? The peak of frequency is the sixth decade, although the disease may develop in younger patients. Signs and symptoms are specific. The main symptoms are: abdominal pain (15 to 60% of patients), weight loss (30 to 59%), nausea and vomiting (25 to 30%), jaundice (20 to 30%), hemorrhage (10 to 38%). A palpable abdominal mass is found in less than 5% of the patients .
Barium studies of the upper intestinal tract have been replaced by fiberoptic endoscopy. Barium examination show in most cases an irregular stricture of the duodenum, but can be normal or lead to the diagnostic of benign stricture. Fiberoptic endoscopy allows a precise location of the tumor and endoscopic biopsies which confirm the diagnosis.
No study has evaluated the best method of preoperative staging of malignant lesions of the duodenum. Some authors use ultrasonography for the diagnosis of liver metastases; the accuracy of CT Scan, IRM and angiography have not been studied. These investigations are not performed routinely, most of the patients being operated on if only for a palliative procedure.
Endoscopic ultrasonography has been reported to be useful for the preoperative staging of ampullary and pancreatic carcinomas. No study reports its accuracy in the preoperative evaluation of malignant duodenal tumors. Five to 40% of the patients have distant metastases or peritoneal seeding at the time of diagnosis .
Due to the low incidence of the disease there is no randomized study comparing different types of treatment. Complete surgical resection is the only hope for cure. Two types of surgical resection are available: pancreatoduodenectomy associated with various types of lymphadenectomies or segmental resections (7, 8). Pancreatoduodenectomy has been advocated as the surgical procedure of choice because it offers the possibility of regional lymph node resection. Nonetheless good long-term results have been observed with segmental resection, particularly for tumors of the distal part of the duodenum . When local extension or metastatic disease preclude curative resection, palliative procedures such as gastrojejunal anastomosis can be performed. Laser photocoagulation has been proposed for patients unfit for surgery with good palliation on hemorrhage and obstructive symptoms.
Radiotherapy and chemotherapy have been used in few cases most often as an adjuvant postoperative treatment with no improvement in outcome. Only one study has shown a complete response in 4 patients treated preoperatively by radio-chemotherapy. The treatment was completed by duodenopancreatectomy and all patients are alive 12 to 90 months after treatment (10). Nonetheless, no sound conclusions on the efficacy of these treatments can be established.
An increased risk of developing small bowel adenocarcinoma has been described in patients with Crohn’s disease (40- to 100-fold increase in relative risk),familial adenomatous polyposis (FAP, 50- to 300-fold),and hereditary nonpolyposis colorectal cancer (HNPCC, > 100-fold).In a study involving HNPCC patients who developed small bowel adenocarcinomas, mismatch repair gene mutations were noted in 36% (15 of 42 patients). In 57% of the patients, the small intestine was the first site of carcinoma, suggesting that small bowel cancer can be the presenting neoplasm in HNPCC patients.
Japan-Hawaii Cancer Study
Stemmermann et al reported the results of the Japan-Hawaii Cancer Study (JHCS), which identified four small bowel adenocarcinomas (0.05%) among a cohort of 8,006 Hawaiian-Japanese men followed for a period of 22 years. All the tumors were located in the duodenum or proximal jejunum, and all the patients also had colorectal cancer. In three of the patients, the colorectal cancer was multicentric. The fourth patient also had gastric cancer, and his brother had multicentric colorectal cancer.
Also in this study, three men had leiomyosarcoma of the small intestine and three had adenocarcinoma of the ampulla of Vater. None of these patients had colorectal cancer, and they did not have a family history of gastric or colorectal cancers. The familial clustering of small bowel adenocarcinomas with multicenteric colorectal cancer and gastric cancer led the authors to suggest that there may be a genetic trait that makes these patients susceptible to carcinogens.
Malignant tumors of the duodenum - Surgical Treatment - NCBI Bookshelf
Management of Small Bowel Adenocarcinoma | Cancer Network
Adenocarcinoma of duodenum | Radiology Reference Article | Radiopaedia.org
Last edited by Medical Photos; 09-20-2015 at 07:27 PM.
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