P-121 - Are There the Distinct Endoscopic Ultrasonography Findings of Gastrointestinal Stromal Tumor?

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics GIST
Imaging, Diagnosis and Staging
Presenter J.-O. Kim
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors J.-. Kim1, S.R. Jeon1, H.G. Kim1, T.H. Lee1, J.S. Lee1, S.Y. Jin2
  • 1Soonchunhyang University College of Medicine, Seoul/KR
  • 2Department of Pathology Soonchunhyang University College of Medicine, Seoul/KR

Abstract

Introduction

Most gastrointestinal mesenchymal tumors are benign; However, 10–30% are malignant. Thus, the differentiation of malignant from benign gastrointestinal mesenchymal tumors is essential for clinical management. Endoscopic ultrasonography (EUS) is a valuable imaging tool for this type of neoplasm. However, the ability of EUS to distinguish between benign and malignant mesenchymal tumors remains to be confirmed. Furthermore, little is known about the differentiation between gastrointestinal stromal tumor (GISTs), leiomyomas, and schwannomas using EUS. The aim of this study was to evaluate the features and diagnostic yield of EUS in the diagnosis of GISTs in comparison with those of leiomyomas and schwannomas.

Methods

Seventy-eight patients with suspected GISTs on EUS were retrospectively enrolled. After exclusion, 24 patients with confirmed by immunochemical pathological reports were finally enrolled in this study, and a well–experienced endoscopist retrospectively performed EUS in the patients. A malignant GIST was defined as peritoneal metastasis or invasion of adjacent organs or mitotic activity > 20 on microscopic view at x50 magnification.

Results

Among of the 24 patients, 15 (2 malignant, 7 borderline, and 6 benign) were diagnosed with GIST; 4 with leiomyoma; and 5 with schwannoma on EUS. All the cases of schwannomas showed a homogenous echo but no distinctive features such as cysts, echogenic foci, calcifications, or septum–like structures. Most GISTs showed a heterogenous echo and a higher echo level compared with the leiomyomas and schwannomas. The GISTs more frequently displayed features such as cysts and echogenic foci than did the leiomyomas and schwannomas.

Conclusion

Generally, differentiation between GISTs, and leiomyomas and schwannomas based on EUS findings is difficult. However comparing the echo level, homogenicity, presence of cysts and/or echogenic foci on EUS may provide helpful information to differentiate between these submucosal tumors.