Hindawi Publishing Corporation Case Reports in Oncological Medicine Volume 2012, Article ID 509845, 3 pages doi:10.1155/2012/509845 Case Report Bone Metastases from Gastrointestinal Stromal Tumor: A Case Report Jihen Feki, 1 Racem Bouzguenda, 1 Lobna Ayedi, 2 Moez Bradi, 3 Tahia Boudawara, 2 Jamel Daoud, 4 and Mounir Frikha 1 1 Oncology Department, Habib Bourguiba University Hospital, El Ain Road, 3029 Sfax, Tunisia 2 Pathology Department, Habib Bourguiba University Hospital, El Ain Road, 3029 Sfax, Tunisia 3 Radiology Department, Habib Bourguiba University Hospital, El Ain Road, 3029 Sfax, Tunisia 4 Radiotherapy Department, Habib Bourguiba University Hospital, El Ain Road, 3029 Sfax, Tunisia Correspondence should be addressed to Racem Bouzguenda, racem.bouzguenda@gmail.com Received 6 October 2012; Accepted 5 November 2012 Academic Editors: S. Aksoy and C. Camps Copyright © 2012 Jihen Feki et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Their most common metastatic sites are the liver and the peritoneum, but GISTs rarely metastasize to the bones. We report a case of a 58-year- old man with sternoclavicular joint metastasis from a GIST manifesting 28 months after surgical resection of the small intestine tumor. We will discuss through this paper and a literature review the clinical characteristics, imaging features, and management of this unusual metastatic location of GIST. 1. Introduction Gastrointestinal stromal tumors (GISTs) are the most com- mon mesenchymatous tumors of the gastrointestinal tract [1]. They most commonly occur at the age of over 50 years [2]. In our oncology center of Sfax, we diagnosed thirty cases of GISTs between 2000 and 2010. The most frequent anatomic location of GIST is the stomach (60%) and the small intestine (30%). Five to ten percent of GISTs arise from the colon and rectum, less than 1% are located in the esophagus, and it can originate beyond the gastrointestinal tract in the omentum, mesentery or retroperitoneum [3]. Their most common metastatic sites are the liver and the peritoneum, but GISTs rarely metastasize to the bones. We will discuss through this paper and a literature review the clinical characteristic, imaging features, and management of this unusual metastatic location of GIST. 2. Case Report A 58-year-old man had undergone surgical removal of a small intestine tumor in January 2008. Histological exami- nation showed a gastrointestinal stromal tumor with a 16 cm primary tumor in the jejunum. Immunohistochemistry revealed spindle cells positive for CD117 and CD34. Mitotic activity was low. No adjuvant treatment was available at that time. The patient was clinically stable and followed by serial imaging until May 2010, when he presented a painful sternoclavicular joint tumefaction. The thoracoabdominal CT scan revealed an osteolytic sternoclavicular joint mass (Figure 1) and 3 liver metastases. Bone scintigraphy showed an increasing intensity of tracer uptake localized in the sternoclavicular joint (Figure 3). The patient underwent a biopsy of the sternoclavicular joint mass. Immunohis- tochemical staining demonstrated the tumor cells to be positive for c-kit (CD117) (Figure 5) protein and CD34 protein. The histological features and staining pattern of the tumor cells were consistent with a GIST metastasis (Figures 4 and 5). Our patient received radiation therapy at the sternoclavicular joint with a total dose of 30 grays. Afterward he began treatment with oral imatinib mesylate at a dose of 400 mg/day. The clinical response was good and the patient’s pain resolved. Control contrast-enhanced CT scans showed a partial response in bone lesion (Figure 2) as well as in liver metastases. After 19 months, the patient complained of weakness of lower limbs. Our patient refused vertebromedullary