Comparison of the Diagnostic Ability of Endoscopic Ultrasonography and Abdominopelvic Computed Tomography in the Diagnosis of Gastric Subepithelial Tumors

Abstract

Background/aims: Endoscopic ultrasonography (EUS) is the most efficient imaging modality for gastric subepithelial tumors (SETs). However, abdominopelvic computed tomography (APCT) has other advantages in evaluating the characteristics, local extension, or invasion of SETs to adjacent organs. This study aimed to compare the diagnostic ability of EUS and APCT based on surgical histopathology results.

Methods: We retrospectively reviewed data from 53 patients who underwent both EUS and APCT before laparoscopic wedge resection for gastric SETs from January 2010 to December 2017 at a single institution. On the basis of histopathology results, we assessed the diagnostic ability of the 2 tests.

Results: The overall accuracy of EUS and APCT was 64.2% and 50.9%, respectively. In particular, the accuracy of EUS vs. APCT for the diagnosis of gastrointestinal stromal tumors (GISTs), leiomyomas, and ectopic pancreas was 83.9% vs. 74.2%, 37.5% vs. 0.0%, and 57.1% vs. 14.3%, respectively. Most of the incorrect diagnoses with EUS involved hypoechoic lesions originating in the fourth echolayer, with the most common misdiagnosed lesions being GISTs mistaken for leiomyomas and vice versa.

Conclusion: APCT showed a lower overall accuracy than EUS; however, APCT remains a useful modality for malignant/potentially malignant gastric SETs.

Keywords: Abdominopelvic computed tomography; Diagnosis; Endoscopic ultrasonography; Subepithelial tumor.

Fig. 1.

Distribution of gastric subepithelial tumors: (A) leiomyoma, (B) gastrointestinal stromal tumor, and (C) ectopic pancreas.

Fig. 2.

Leiomyoma was misdiagnosed as a gastrointestinal stromal tumor (GIST) based on endoscopic ultrasonography (EUS) findings in a 37-year-old man (Table 4, case 4). (A) Upper endoscopy showed a gastric subepithelial tumor with a size of about 5.0 cm on the cardia. (B) EUS showed a 5.2-cm, well-defined, hypoechoic with a heterogeneous echotexture, and septated lesion mainly originating in the fourth layer. The lesion was presumed to be a GIST. (C) Contrast-enhanced computed tomography axial image showed a 5.1-cm, well-demarcated, and outward-protruding mass with homogeneous enhancement on the cardia. The lesion was presumed to be a GIST. (D) The histopathological result of surgical resection was leiomyoma with a size of 5.2 cm, which was composed of spindle cells as observed on hematoxylin and eosin staining (×10). (E) Immunohistochemical staining was negative for c-kit (×40). (F) Immunohistochemical staining was positive for actin (×40).