Gastrointestinal Stromal Tumor (GIST) Diagnosis

• Physical Examination and Medical History: The doctor will start with a detailed medical history and a physical examination to check for any abnormalities.
• Imaging Studies:
  
  • CT Scan: Provides detailed images of the abdomen to identify the size and location of the tumor.
  • MRI: Offers detailed images, particularly useful for examining soft tissues.
  • PET Scan: Helps to determine if the cancer has spread to other parts of the body.
• Endoscopy:
  
  • Upper Endoscopy (EGD): Involves inserting a thin, flexible tube with a camera into the esophagus, stomach, and small intestine to visualize and possibly biopsy the tumor.
  • Endoscopic Ultrasound (EUS): Combines endoscopy and ultrasound to obtain detailed images and perform a fine-needle aspiration biopsy.
• Biopsy: A tissue sample from the tumor is essential for diagnosis. This can be done during an endoscopy or through a needle biopsy guided by imaging studies.
• Histopathological Examination: The biopsy sample is examined under a microscope to identify the type of cells and confirm the diagnosis of GIST.
• Immunohistochemistry: Special stains are used to detect specific proteins, such as CD117 (KIT) and DOG1, which are commonly present in GIST cells.
• Molecular Genetic Testing: Genetic tests may be performed to identify mutations in the KIT or PDGFRA genes, which can help in determining the most effective treatment plan.