From the Guidelines
Small bowel tumors commonly present with nonspecific symptoms, including abdominal pain, unexplained weight loss, and gastrointestinal bleeding, which can lead to delayed diagnosis. The most frequent presentations include abdominal pain (which may be intermittent or cramping), unexplained weight loss, and gastrointestinal bleeding (either occult bleeding causing iron deficiency anemia or overt bleeding with melena or hematochezia) 1. Patients may also experience nausea, vomiting, and changes in bowel habits. In cases where tumors grow large enough to obstruct the intestinal lumen, symptoms of small bowel obstruction can develop, including severe abdominal pain, distension, and vomiting. Some patients present with intussusception, where the tumor acts as a lead point causing telescoping of the bowel. Malignant tumors may present with more constitutional symptoms like fatigue, fever, and night sweats.
- The symptoms of small bowel tumors can be vague and nonspecific, making diagnosis challenging.
- Gastrointestinal stromal tumors (GISTs) are a type of small bowel tumor that can present with a range of symptoms, including abdominal pain, bleeding, and weight loss 1.
- The diagnosis of small bowel tumors often relies on a combination of imaging studies, endoscopy, and biopsy, with molecular analysis playing an increasingly important role in guiding treatment decisions 1.
- Small bowel GISTs may remain silent for a long period before presenting with an acute event such as haemorrhage or rupture, and some patients may have non-specific systemic symptoms e.g. weight loss, night sweats and fever 1.
- Some patients present with intussusception, where the tumor acts as a lead point causing telescoping of the bowel, and malignant tumors may present with more constitutional symptoms like fatigue, fever, and night sweats.
- Carcinoid tumors specifically can cause carcinoid syndrome (flushing, diarrhea, and wheezing) when they metastasize to the liver.
- The nonspecific nature of these symptoms often results in diagnostic delays, with many tumors discovered incidentally during imaging studies or endoscopic procedures performed for other reasons.
- Multidisciplinary treatment planning is needed, involving pathologists, radiologists, surgeons and, medical oncologists, as well as gastroenterologists, nuclear medicine specialists, etc., as applicable 1.
- Management should be carried out in reference centers for sarcomas and GISTs and/or within reference networks sharing multidisciplinary expertise and treating a high number of patients annually 1.
From the Research
Common Presentation of Small Bowel Tumors
- The most common symptoms of small bowel tumors are:
- Abdominal pain (reported in 66.7% of patients in 2, 67% in 3, and 89.7% in 4)
- Weight loss (reported in 57.6% of patients in 2, 38% in 3, and 77% in 4)
- Nausea and vomiting (reported in 5)
- Gastrointestinal hemorrhage (more common in benign tumors, as reported in 5)
- Obstruction (more common in metastatic tumors, as reported in 5)
- The presentation of small bowel tumors can be nonspecific and may resemble other abdominal conditions, making diagnosis challenging 2, 5, 3
- The location of the tumor can also affect the presentation, with tumors in the duodenum, jejunum, and ileum having different frequencies and symptoms 2
Diagnostic Challenges
- Small bowel tumors are difficult to diagnose due to their rarity and nonspecific symptoms 2, 5, 3
- Diagnostic tools such as upper gastrointestinal series, endoscopy, computed tomography scan, and selective angiography can be useful in diagnosing small bowel tumors 3
- Small-bowel capsule endoscopy, device-assisted enteroscopy, and dedicated small-bowel cross-sectional imaging are also complimentary tools in the diagnostic process 6
Tumor Types and Frequencies
- The most common malignant tumors of the small bowel are:
- Benign tumors, such as leiomyomas and adenomas, can also occur in the small bowel 3