Contrast Enhanced Harmonic Endoscopic Ultrasound: A Novel Approach for Diagnosis and Management of Gastrointestinal Stromal Tumors

The histologic analysis of gastrointestinal stromal tumors (GISTs) is a common method to detect the mitotic activity and to subsequently determine the risk of GISTs for malignancy. The potential false negative error due to inadequate yield of specimens and actual determination of malignancy risk requires analysis of the whole tumor. We aimed to assess the role of contrast enhanced endoscopic ultrasound (CE-EUS) in the management of GISTs. Two authors individually did review of English literatures to identify nine peer-reviewed original articles using keywords- contrast endoscopic ultrasound, GIST and submucosal tumor. Studies were heterogeneous in their aims looking either at differentiating submucosal lesions from GISTs, estimating malignant potential of GISTs with histologic correlation or studying the role of angiogenesis in malignant risk stratification. CE-EUS had moderate to high efficacy in differentiating GISTs from alternative submucosal tumors. CE-EUS had a higher sensitivity than EUS-guided fine needle aspiration, contrast computed tomography and Doppler EUS for detection of neo-vascularity within the GISTs. However, the evidence of abnormal angiogenesis within GIST as a prognostic factor needs further validation. CE-EUS is a non-invasive modality, which can help differentiate GISTs and provide valuable assessment of their perfusion patterns to allow better prediction of their malignant potential but more experience is needed.