The neo-adjuvant treatment in gastrointestinal stromal tumor.

Gastrointestinal Stromal Tumor (GIST) is a rare intra-abdominal tumor, characterized by a specific histological and immunohistochemical pattern. These tumors affect with higher frequency stomach and small bowel and occur at a median age of 60 years with a slight male predominance. An early stage of GIST often don't cause any symptoms, so most GISTs are diagnosed in later stages of the disease. We report a case of GIST diagnosed only with clinical data and positron emission tomography (PET). We demonstrate the usefulness of neoadjuvant treatment with Imatinib mesylate, a newly developed tyrosine kinase receptor inhibitor. The neoadjuvant treatment with Imatinib reduced the mass size and vascularization, making possible a surgical approach.