Endoscopic ultrasound-guided tru-cut biopsy for diagnosis of gastrointestinal stromal tumors.

Background/Aims: The most common mesenchymal tumors of gastrointestinal tract are gastrointestinal stromal tumors (GIST). These tumors originate from muscularis propria layer. Tissue diagnosis is usually difficult by endoscopic mucosal biopsy. The aim of this study is to evaluate the utility of endoscopic ultrasound-guided Tru-Cut biopsy (EUS-TCB) for GISTs before treatment. Methodology: A total of six patients in the period between June 2006 and May 2009 were included in this study. EUS-TCB was performed with a 19-gauge core needle to obtain sufficient specimen for pathological and immunohistochemical studies. All tumor sizes were larger than 2cm. Specimen size and the number of needle passes were both recorded. Results: Core tissues were successfully procured by EUS-TCB in all tumors (100%). The mean tumor size was 50mm (range 30-75mm). The final pathological diagnosis was c-kit positive stromal tumor in five patients and leiomyoma in one patient. The mean size of specimen was 8 mm (range 3-13mm) and the mean number of needle passes was 2 (range 1-3). No patient developed complications after the procedure. Conclusion: EUS-TCB is a safe, quicker procedure that offers sufficient tissue acquisition for pathological diagnosis and clinical decision-making in patients with GISTs.