Small-bowel tumors account for 1 to 5% of gastrointestinal tumors. Small-bowel cancer accounts for an estimated 12,070 cases and about 2,070 deaths in the United States annually (1). Diagnosis is by enteroclysis. Treatment is surgical resection.
Benign tumors include leiomyomas, lipomas, neurofibromas, and fibromas. All may cause abdominal distention, pain, bleeding, diarrhea, and, if obstruction develops, vomiting. Polyps are not as common as in the colon.
Adenocarcinoma, a malignant tumor, is uncommon. Usually it arises in the duodenum or proximal jejunum and causes minimal symptoms. In patients with Crohn disease involving the small-bowel, the tumors tend to occur distally and in bypassed or inflamed loops of bowel.
Primary malignant lymphoma arising in the ileum may cause a long, rigid segment. Small-bowel lymphomas can arise in long-standing, untreated celiac disease.
Gastrointestinal neuroendocrine tumors (previously known as carcinoid tumors) occur most often in the small bowel, particularly the ileum, and in the appendix; in these locations, larger lesions can become malignant. Multiple tumors occur in 50% of cases. Of those > 2 cm in diameter, 80% have metastasized locally or to the liver by the time of operation. About 30% of small-bowel neuroendocrine tumors cause obstruction, pain, bleeding, or carcinoid syndrome. Treatment of these tumors depends on the site of origin. Small-bowel neuroendocrine tumors are surgically resected; repeat operations may be required, and, in many cases, more than one segment of small intestine is involved. Gastric neuroendocrine tumors, unlike those of the small intestine, can be managed with endoscopic resection if they are small and associated with chronic atrophic gastritis (eg, type 1 disease). Similarly, small rectal neuroendocrine tumors sometimes can be removed endoscopically. For metastatic neuroendocrine tumors, long-acting somatostatin analog therapy with dose escalation, peptide receptor radioligand therapy (PRRT) using a radiolabeled somatostatin
Kaposi sarcoma, occurs in an aggressive form in patients who are immunocompromised (eg, transplant recipients, patients with uncontrolled AIDS). Lesions may occur anywhere in the GI tract but usually in the stomach, small bowel, or distal colon. GI lesions usually are asymptomatic, but bleeding, diarrhea, protein-losing enteropathy, and intussusception may occur. Treatment of Kaposi sarcoma depends on the cell type and location and extent of the lesions.
General reference
1. Siegel RL, Miller KD, Wagle NS, Jemal A: Cancer statistics, 2023. CA Cancer J Clin 73(1):17–48, 2023. doi: 10.3322/caac.21763
Diagnosis of Small-Bowel Tumors
Enteroclysis
Sometimes push endoscopy or capsule video endoscopy
Enteroclysis (sometimes CT enteroclysis) is probably the most common study for mass lesions of the small bowel. Enteroclysis involves administration of contrast into the stomach followed by fluoroscopic imaging via a series of x-rays to visualize intestinal motility and wall abnormalities. CT enteroclysis combines enteroclysis with standard abdominal CT.
Push endoscopy of the small bowel with an enteroscope may be used to visualize and biopsy tumors.
Video capsule endoscopy can help identify small-bowel lesions, particularly bleeding sites; a swallowed capsule transmits 2 images/second to an external recorder. The original capsule is not useful in the stomach or colon because it tumbles in these larger organs; a colon capsule camera with better optics and illumination is under development for use in these larger-diameter organs.
Treatment of Small-Bowel Tumors
Surgical resection
Treatment of small-bowel tumors is surgical resection.
Electrocautery, thermal obliteration, or laser phototherapy at the time of enteroscopy or surgery may be an alternative to resection.
