Less Common Tumors of the Bowel

Senior woman feeling pain while consulting doctor on her smart phone
Gastrointestinal tract. Human intestine and stomach organ. Medical illustration

The bowel includes the small and large intestines, parts of your digestive system. Bowel tumors are a general term for cancer that begins anywhere in the bowel. There are several less common cancerous tumors that can affect the bowel including gastrointestinal stromal tumors (GISTs), carcinoids and lymphoma.

General Questions

What are gastrointestinal stromal tumors (GISTS)?
GISTs are small, slow-growing tumors found primarily in the stomach (where the bowel begins). However, GISTs can also occur in the small intestine, esophagus, colon, rectum and the tissue connecting these organs.
What are neuroendocrine tumors (carcinoids)?
Neuroendocrine tumors are very slow-growing and most commonly found in the appendix, ileum (the last part of the small intestine) and rectum. However, these tumors can grow in many other organs as well, including the lungs and pancreas.
What is lymphoma?
Lymphoma is a cancer that starts in the cells of the lymphatic system (part of the immune system). Sometimes, lymphoma can spread from the lymphatic system and attack other organs in the body, including the digestive tract. The stomach is the most common site for lymphoma, followed by the small bowel and the colon.
Causes of bowel tumors

Though doctors do not know what causes tumors to grow in the bowel, risk factors for various bowel tumors include:

  • Age (especially over 65)
  • Family history of bowel cancer
  • Gender (males are more at risk)
  • Having certain genetic syndromes or mutations, including:
    • Multiple endocrine neoplasia type 1 (MEN 1)
    • Multiple endocrine neoplasia type 2 (MEN 2)
    • Neurofibromatosis
    • Tuberous sclerosis
    • Von Hippel-Lindau disease
  • Heavy alcohol use
  • Smoking
Symptoms of bowel tumors

If the bowel tumor is small, most people won’t experience any symptoms. Typically doctors only discover a cancerous growth when investigating another medical problem. If the tumor is in the intestines and is large enough, it may cause symptoms similar to other colon cancers, such as:

  • Abdominal pain
  • Bleeding from the rectum or bloody stools
  • Bloating
  • Change in bowel habits
  • Unexplained weight loss
Surgical treatment for bowel tumors

The standard treatment for GISTs and neuroendocrine tumors (carcinoids) is to remove the cancerous growth, and whichever part of the bowel is affected. Depending on the type and size of the tumor, surgeons may also recommend chemotherapy as follow-up therapy.

For lymphoma, immediate chemotherapy may be the first-line treatment if it is an option. Surgeons typically reserve surgery to remove the lymphoma for those tumors blocking or tearing the bowel. Specialists can also use radiation to treat some rectal lymphomas. Your North Carolina Surgery team will help you plan the most effective treatment for your bowel tumors based on factors that we will discuss during your consultation in our clinic.