title: Can contrast-enhanced harmonic endosonography predict malignancy risk in gastrointestinal subepithelial tumors?
abstract: OBJECTIVE
  Contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) is a novel technology that can identify subepithelial tumors (SETs) by detecting the degree of enhancement, but whether CEH-EUS can predict the malignancy risk of gastrointestinal stromal tumors (GISTs) remains unclear. The aim of our study was to evaluate the diagnostic accuracy of CEH-EUS and its ability to discriminate among SETs and predict the malignancy risk of GISTs.
  
  
  METHODS
  We retrospectively included patients with suspected subepithelial lesions who underwent CEH-EUS preoperatively. Thirty-five patients with histologically proven GISTs and benign neoplasms were enrolled in the study. The images of CEH-EUS were categorized in accordance with microvasculature, parenchymal perfusion, and nonenhancing spots. The diagnostic performance of CEH-EUS was evaluated by comparing these findings with the histological diagnosis.
  
  
  RESULTS
  When we divided the enrolled patients into high- and low-grade malignancy and benign groups, nonenhancing spots on CEH-EUS were found more frequently in the high-grade malignancy group (63.6%), followed by the low-grade malignancy (46.7%) and benign groups (25.7%) (P = 0.022). However, based on the statistical validity of the CEH-EUS findings for the discrimination of SETs, the sensitivity was 53.8% for diagnostic performance and 63.6% for prediction of malignancy risk of GISTs.
  
  
  CONCLUSIONS
  From our study results, it is unclear whether CEH-EUS alone has a diagnostic role in the discrimination of SETs and the prediction of malignancy risk of GISTs. Further studies with larger samples from multiple centers and use of other imaging analysis modalities are needed.
authors.affiliation: Department of Internal Medicine, Kyungpook National University Medical Center, Daegu, South Korea.
authors.forename: Hye Yoon
authors.initials: HY
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Kyungpook National University Medical Center, Daegu, South Korea.
authors.forename: Seong Woo
authors.initials: SW
authors.lastname: Jeon
authors.affiliation: Department of Internal Medicine, Kyungpook National University Medical Center, Daegu, South Korea.
authors.forename: Hyun Seok
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Kyungpook National University Medical Center, Daegu, South Korea.
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Cho
authors.affiliation: Department of Pathology, Kyungpook National University Medical Center, Daegu, South Korea.
authors.forename: Han Ik
authors.initials: HI
authors.lastname: Bae
authors.affiliation: Department of Pathology, Kyungpook National University Medical Center, Daegu, South Korea.
authors.forename: An Na
authors.initials: AN
authors.lastname: Seo
authors.affiliation: Department of Surgery, Kyungpook National University Medical Center, Daegu, South Korea.
authors.forename: Oh Kyung
authors.initials: OK
authors.lastname: Kweon