Mandibular metastases from an ileum stromal tumor.

INTRODUCTION: Metastatic disease of the jaws is unusual and accounts for 1 to 4% of oral cavity malignancies. Jaw metastases from the gastrointestinal (GI) tract usually evolve from adenocarcinoma of the esophagus, colon, and rectum. Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the GI tract defined by a positive C-Kit (CD117). These tumors are thought to arise from Cajal cells in GI tract walls, essential for intestine motor function. The small intestine harbors only 30% of GIST. After reviewing the literature, no case of jaw metastases from GIST was found. The purpose of this study was to report the first case of mandibular metastases arising from a stromal tumor of the ileum. CASE REPORT: A 68-year-old man presented with a painful swelling in the parasymphysis and left molar mandibular area having grown progressively for 3 weeks. The oral mucosa was macroscopically normal. The orthopantomograph showed radiolucency. A CT-Scan revealed an irregular osteolytic lesion with invasion of soft-tissues. Biopsy proved a stromal tumor. A complete CT-Scan analysis revealed an ileum tumor. Biopsies and immunochemistry proved an ileum stromal tumor. All tumoral cells expressed the C-Kit in the ileum and the mandible. The patient was treated with imatinib but died 11 months after the diagnosis. DISCUSSION: The prevalence of GIST is low but the true incidence may be higher because of under-diagnosis. To our knowledge, this is the first well-documented case report of jaw metastasis from ileum GIST. GIST should be included in the differential diagnosis of intramandibular tumor in patients with prior or current non-oral malignancy.