Gastrointestinal Stromal Tumors
Gastrointestinal stromal tumors (GISTs) are cancerous (malignant) tumors that develop from a specific kind of cell (mesenchymal precursor cells) within the wall of the esophagus, stomach, or intestines. Most GISTs are caused by a mutation in a gene called C-KIT that controls the growth of cells. Most (60 to 70%) of these tumors occur in the stomach, 20 to 25% occur in the small intestine, and a small percentage occurs in the esophagus, colon, and rectum.
The average age at diagnosis is 50 to 60. People who have had radiation therapy to the abdomen for the treatment of other tumors can develop GISTs at a later time. These tumors usually grow slowly, but some can grow more rapidly and spread to other sites (metastasize).
Symptoms
Symptoms of gastrointestinal stromal tumors depend on the location of the tumor but include abdominal pain, bleeding, indigestion, and a feeling of fullness after eating a small meal. Nausea and vomiting can occur if the tumor has grown large enough to block the digestive tract.
An additional variable finding sometimes associated with Menetrier disease is the loss of protein from the circulation into the gastrointestinal tract (protein-losing gastropathy) such as the loss of the protein albumin (hypoalbuminemia). Protein loss may be severe in some cases. Protein loss may result in fluid accumulation (edema), especially in the legs.
Gastrointestinal bleeding has also been reported in some cases of Menetrier disease usually as a result of erosions or ulcers in the stomach lining. Acid secretion by the stomach is often markedly decreased (hypochlorhydria) or absent. Excess mucous secretion in the stomach may also occur.
Some researchers believe that individuals with Menetrier disease have a greater risk of developing gastric cancer than the general population has. However, other researchers do not believe this to be proven with certainty. In some series, there has been an association between Menetrier disease and ulcerative colitis.
Diagnosis
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Endoscopy or colonoscopy
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Imaging tests
A doctor may use an endoscope or colonoscope to locate the tumor and do a biopsy (remove a tissue sample for examination under a microscope). A wireless battery-powered capsule that contains one or two small cameras can also be used to show tumors of the small intestine; however, this techniques does not allow biopsies.
To determine whether the cancer has spread to other organs, doctors do a computed tomography (CT) scan of the abdomen or endoscopic ultrasonography (in which an ultrasound probe is placed on the tip of the endoscope and shows the lining of the digestive tract more clearly than many other tests).
Treatment
If the cancer has not spread to other organs, doctors remove it surgically. If the cancer has spread, doctors often treat with a certain type of chemotherapy drug (imatinib).
