824 Case report Gastrointestinal stromal tumor complicated by Streptococcus milleri bacteremia and liver abscess Yong Kwon a , Ngoc-Duyen T. Dang b and Badih Joseph Elmunzer b Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Often discovered incidentally, GISTs can present with nonspecific abdominal symptoms or more overt symptoms of bleeding, obstruction, or perforation. Despite a myriad of clinical presentations, bacteremia associated with a GIST has not been described. In this report, we present an unusual clinical case that illustrates how GISTs can become infected, and demonstrate the importance of Streptococcus milleri bacteremia as an indicator of possible underlying gastrointestinal neoplasm. Eur J Gastroenterol Hepatol 21:824–826  c 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins. European Journal of Gastroenterology & Hepatology 2009, 21:824–826 Keywords: gastrointestinal neoplasm, gastrointestinal stromal tumor, liver abscess, Streptococcus milleri bacteremia, Streptococcus milleri a Department of Internal Medicine and b Division of Gastroenterology, University of Michigan Medical Center, Ann Arbor, Michigan, USA Correspondence to Yong M. Kwon, MD, Department of Internal Medicine, 2F208 UH, Box 0052, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-0052, USA Tel: +1 734 936 4000; fax: +1 734 936 3654; e-mail: yongkwon@umich.edu Received 6 September 2007 Accepted 8 February 2008 Introduction Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal tract [1]. These lesions originate from the interstitial cell of Cajal and generally express c-KIT (CD114), a tyrosine kinase receptor that has become the primary target for molecular therapy of this malignancy [2,3]. GISTs are generally discovered incidentally, although they can become symptomatic, most commonly presenting with bleeding or obstruction [4]. Other manifestations include nonspecific symptoms such as abdominal pain, nausea, and anorexia [5], or more unusual presentations such as spontaneous perforation and paraneoplastic hypoglycemia [6,7]. Despite myriads of clinical presentations, sponta- neous infection of a GIST with associated bacteremia has not been described. In this report, we present a case of GIST complicated by Streptococcus milleri bacteremia and liver abscess. This unusual clinical presentation illus- trates that gastrointestinal stromal tumors can become infected and reinforces the importance of recognizing S. milleri as an indicator of possible underlying gastro- intestinal neoplasm. Case report A previously healthy 42-year-old woman presented to our emergency department with 1 day of right upper quadrant abdominal pain and fever of 1031F. Physical examination was remarkable for tenderness to palpation in the upper abdomen. Laboratory evaluation revealed a white blood cell count of 14 000/mm 3 , mild transaminitis with AST 48 and ALT 56, as well as profound iron deficiency anemia with a Hgb of 8.7 g/dl and ferritin of 7 ng/ml. Blood for culture grew S. milleri in all four bottles. Computed tomography (CT) of the abdomen with oral and intravenous contrast revealed a 5-cm heterogeneously enhancing mass in the right retroperitoneum posterior to, and abutting the third portion of the duodenum (Fig. 1). An associated soft tissue stranding and necrosis, indica- tive of surrounding inflammation was observed. In addition, several low-attenuation lesions were seen in the right hepatic lobe. Serum carcinoembryonic antigen and CA 19-9 were normal. An upper endoscopy revealed a near-obstructing sub- epithelial mass with central area of ulceration. Mucosal biopsies of the lesion were nondiagnostic. An endoscopic ultrasound (EUS) revealed an irregular, hypoechoic, heterogeneous mass in the region of the pancreatic head, likely originating from the muscularis propria of the duodenum (Fig. 2). Cytologic evaluation of an EUS- guided aspirate (fine needle aspiration, FNA) from the mass demonstrated a spindle cell neoplasm on the background of an acute inflammatory process (Fig. 3). Microbiological culture of the same aspirate grew S. milleri. CT-guided FNA of the dominant liver lesion revealed abscess tissue without neoplastic features. Given the EUS-FNA findings and the near obstructing nature of the mass, a Whipple resection was performed. This procedure was technically successful with complete removal of all involved tissue. Cross-section of the resected tissue revealed a 3.5 cm duodenal wall mass with an associated large hemorrhagic area adjacent to the mucosal surface. Histopathologic evaluation revealed a hypocellular GIST that was cytologically bland, without appreciable mitotic features, consistent with a benign 0954-691X  c 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI: 10.1097/MEG.0b013e3282fc735c Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.