Contrast-enhanced (endoscopic) ultrasound and endoscopic ultrasound elastography in gastrointestinal stromal tumors

Abstract

Background and Objectives:Gastrointestinal stromal tumors (GISTs) represent the largest group of subepithelial tumors (SET) of the upper gastrointestinal (GI) tract. They may show malignant behavior, in contrast to other SET. Endoscopic ultrasound (EUS) is frequently used to characterize SET. With the introduction of contrast-enhanced ultrasound (CEUS) into EUS (CE-EUS), distinct enhancement patterns can be detected. In the presented study, the characteristic features of CE-EUS in GIST are analyzed and compared with those of other SET.Materials and Methods:Consecutive patients from four centers with SET of the upper and middle GI tract were included and received endoscopic or transcutaneous CEUS. The results were compared with EUS-guided tissue acquisition, forceps biopsy, or surgical resection.Results:Forty-two out of 62 (68%) patients had SET of the stomach, 17/62 (27%) of the small intestine, 2/62 (3%) of the esophagus, and 1/62 (2%) extraintestinal. Eighty-one percent underwent surgery. Leiomyoma was found in 5/62 (8%) and GIST in 57/62 patients (92%). Thirty-nine out of 57 (68%) patients had GIST lesions in the stomach, 17/57 (30%) had GIST of the small intestine, and 1/57 (2%) patients had extraintestinal GISTs. GIST size was 62.6 ± 42.1 (16–200) mm. Hyperenhancement had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 98%, 100%, 100%, 93%, and 98% for the diagnosis of GIST. Fifty out of 57 patients with GIST (88%) showed avascular areas in the center of the lesions.Conclusion:CE-EUS and CEUS show hyperenhancement and avascular areas in a high percentage of GIST but not in leiomyoma. Thus, GIST and leiomyoma can be discriminated accurately.

Value of contrast‐enhanced harmonic endoscopic ultrasonography in differentiating between gastrointestinal stromal tumors: A meta‐analysis

“…Most of studies noted that EUS examination was performed or reviewed by at least two experienced endosonographers. A total of four studies involving 187 individuals were examined to assess the diagnostic accuracy of CH‐EUS in discriminating between GIST and benign SML . GIST were identified according to parenchymal perfusion in three studies and based on the simultaneous determination of the microvasculature pattern, parenchymal perfusion, and non‐enhancing spots in one study.…”

“…Malignant potential was determined based on mitotic activity. Low malignant potential was indicated by a mitotic activity of ≤5 figures per 50 high‐power fields (HPF) in three studies, while one used <10 figures/50 HPF, and the criterion in the other study was not available.…”

“…Currently, CH‐EUS is widely used in the diagnosis and differential diagnosis of pancreatic and intraperitoneal space‐occupying lesions. Recently, some studies have reported the value of CH‐EUS in gastrointestinal diseases, particularly for distinguishing between GIST and benign subepithelial lesions as well as for predicting the malignant potential of GIST . In the current meta‐analysis, we aimed to evaluate the overall sensitivity, specificity, and accuracy of CH‐EUS in the differential diagnosis and determination of the malignant potential of GIST.…”

Non-invasive evaluation of intestinal disorders: The role of elastographic techniques

“…However, not only further evidence but also further technological advancements are needed before elastography can be routinely applied to the diagnosis of malignant intestinal lesions, and also preliminary data on the application of this technique for the diagnosis of gastrointestinal stromal tumors seem to suggest the same[55]. …”

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“…For high frequency applications 4.8 ml is suggested. In particular, endoscopic ultrasound usually requires the complete vial of 4.8 ml [51][52][53]. For the extravascular (intraluminal) use only few drops diluted in normal saline solution are necessary.…”