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The patient was taken to the operating room and first underwent diagnostic laparoscopy revealing a significant amount of periappendiceal purulent fluid. The appendix was removed laparoscopically. The procedure was then converted to an open exploration through a periumbilical midline incision. An approximately 5 × 5-cm pedunculated mass was identified arising from the proximal jejunum approximately 40 cm from the ligament of Treitz (Figure 2). Perforation of the mass with its associated bowel was noted, and no other abnormalities were noted. The involved segment of bowel with its associated mesentery was resected with 10-cm margins and a stapled anastomosis performed.

Small-bowel cancers are relatively rare. Adenocarcinomas are the most common, typically located in the duodenum. Small-bowel tumors most often present with nonspecific symptoms such as pain and cramping but can also present with hemorrhage, as was most likely the case with this patient who had melena a month prior to this admission when he presented with peritonitis secondary to perforation.^1- 2

On final pathologic review, this patient was found to have a gastrointestinal stromal tumor (GIST). Gastrointestinal stromal tumors account for only 14% of small-bowel neoplasms and most commonly (60%) arise from the stomach.³Though extraluminal in origin as mesenchymal tumors, they can perforate through the mucosa as well as intraperitoneally, as was the case with this patient. On pathologic examination, this patient had an 8-cm tumor with more than 5 mitoses per 50 high-power fields, suggesting a high-risk tumor.⁴The tumor core was necrotic, leading to perforation, further classifying this as a high-risk tumor. The tumor was c-KIT (CD117) positive and negative for S-100 and desmin, all typical for GISTs.^3,5Margins and associated mesenteric lymph nodes were negative.

Complete tumor resection with negative margins is the definitive treatment for GIST, with routine lymphadenectomy unnecessary as lymph node extension is very rare. Effective treatment of GISTs with activating mutations in the proto-oncogene C-KIThas been achieved with imatinib mesylate in a number of recent studies.^3- 4,6- 7Mutations in c-KITand the platelet-derived growth factor receptor α gene (PDGFRA) have been used to predict response to imatinib^3,5but were unavailable in this patient. A number of ongoing trials are evaluating adjuvant treatment with imatinib.⁸

The differential diagnosis in this patient also included Mediterranean intestinal lymphoma. This is typified by diffuse bowel thickening and multiple lesions resulting from lymphoplasmacytic infiltration of the bowel wall. These malignancies are low-grade B-cell mucosa-associated lymphoid tissue lymphomas. However, patients do not classically present with bleeding and perforation. Parasitic and bacterial intestinal infections are present in many patients and early disease is often responsive to antibiotic therapy.^9- 10

This patient recovered uneventfully and was discharged home with plans to start imatinib therapy in 6 weeks.

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Accepted for Publication:March 12, 2007.

Correspondence:Mitchell Jay Cohen, MD, Department of Surgery, San Francisco General Hospital, Ward 3A, 1001 Potrero Ave, San Francisco, CA 94110 (mcohen@sfghsurg.ucsf.edu).

Author Contributions:Study concept and design: Lord, Ozgediz, and Cohen. Acquisition of data: Lord and Ozgediz. Analysis and interpretation of data: Lord and Ozgediz. Drafting of the manuscript: Lord and Ozgediz. Critical revision of the manuscript for important intellectual content: Lord, Ozgediz, and Cohen. Administrative, technical, and material support: Lord and Ozgediz. Study supervision: Lord and Cohen.

Financial Disclosure:None reported.