How is GIST diagnosed?
• Vague abdominal discomfort or pain. • Presence of a palpable abdominal mass. • Feeling of abdominal fullness. • Secondary symptoms resulting from tumor bleeding and associated anemia. A biopsy is commonly used to aid in the diagnosis of cancer and GIST. Tissue samples are prepared from the biopsy sample. One method that the pathologist uses to classify tissues is called immunohistochemistry. Using this technique, the pathologist applies various “antibodies” to the tissues. These antibodies react with specific proteins on the cell surface which are characteristic of particular types of cells. The most important antibody that is applied when GIST is suspected is the antibody to the KIT protein. When these antibodies bind to their specific target on the cell surface they produce a “stain” or change in color of the sample. So when the KIT antibody is applied, if the cell surface has the KIT protein present on the surface, the sample will “stain positive”. This is what is known as “KIT po
