Dramatic regression and bleeding of a duodenal GIST during preoperative imatinib therapy: case report and review

Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive tract. The majority of GISTs is located in the stomach. Only 3-5% of GISTs are located in the duodenum associated with an increased risk of gastrointestinal bleeding as primary manifestation. With response rates of up to 90%, but complications like bleeding due to tumor necrosis in 3%, imatinib mesylate dramatically altered the pre- and postoperative therapy for GIST patients. Case presentation: A 58-year-old female patient presented with acute upper gastrointestinal bleeding 2 weeks after a giant GIST of the duodenum had been diagnosed. Neoadjuvant imatinib therapy had been initiated to achieve a tumor downsizing prior to surgery. During emergency laparotomy a partial duodenopancreatectomy was performed to achieve a complete resection of the mass. Histology revealed a high-malignancy GIST infiltrating the duodenal wall. Adjuvant imatinib therapy was initiated. At follow-up (19 months) the patient is still alive and healthy. Conclusion: Giant GISTs of the duodenum are rare and - in contrast to other localizations - harbour a higher risk of serious bleeding as primary manifestation. Tumor necrosis and tumor bleeding are rare but typical adverse effects of imatinib therapy especially during treatment of high-malignancy GIST. In GIST patients with increased risk of tumor bleeding neoadjuvant imatinib therapy should thoroughly be performed during hospitalization. In cases of duodenal GIST primary surgery should be considered as treatment alternative.