title: Endosonographic Features of Gastric Schwannoma: A Single Center Experience.
abstract: OBJECTIVE
  Gastric schwannomas are rare benign mesenchymal tumors that are difficult to differentiate from other mesenchymal tumors with malignant potential, such as gastrointestinal stromal tumors. This study aimed to evaluate the characteristic findings of gastric schwannomas via endoscopic ultrasonography (EUS).
  
  
  METHODS
  We retrospectively reviewed the EUS findings of 27 gastric schwannoma cases that underwent surgical excision at Pusan National University Hospital during 2007 to 2014.
  
  
  RESULTS
  Gastric schwannomas were mainly located in the middle third of the stomach with a mean tumor size of 32 mm. All lesions exhibited hypoechoic echogenicity, and 24 lesions (88.9%) exhibited heterogeneous echogenicity. Seventeen lesions (63.0%) exhibited decreased echogenicity compared to the normal proper muscle layer. Distinct borders were observed in 24 lesions (88.9%), lobulated margins were observed in six lesions (22.2%), and marginal haloes were observed in 24 lesions (88.9%). Hyperechogenic spots were observed in 21 lesions (77.8%), calcifications were observed in one lesion (3.7%), and cystic changes were observed in two lesions (7.4%).
  
  
  CONCLUSIONS
  During EUS, gastric schwannomas appear as heterogeneously hypoechoic lesions with decreased echogenicity compared to the normal proper muscle layer. These features may be helpful for differentiating gastric schwannomas from other mesenchymal tumors.
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Gwang Ha
authors.initials: GH
authors.lastname: Kim
authors.affiliation: Department of Pathology, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Do Youn
authors.initials: DY
authors.lastname: Park
authors.affiliation: Department of Pathology, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Na Ri
authors.initials: NR
authors.lastname: Shin
authors.affiliation: Department of Pathology, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Sangjeong
authors.initials: S
authors.lastname: Ahn
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Chul Hong
authors.initials: CH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Jin Sung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Key Jo
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Bong Eun
authors.initials: BE
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Geun Am
authors.initials: GA
authors.lastname: Song
keywords: Endosonography; Mesenchymal tumor; Schwannoma; Stomach