The following recommendations on the management of gastric subepithelial masses were made by the American Gastroenterological Association Institute:
Masses arising outside the gastric wall or within the wall but beneath the gastric surface epithelium are commonly found during upper gastrointestinal endoscopy, although their precise incidence is unknown. Standard forceps biopsy is unlikely to provide a tissue diagnosis, leading to diagnostic uncertainty for the physician and the patient. The differential diagnosis of these masses is broad and ranges from clinically insignificant to malignant conditions, underlining the importance of making an accurate diagnosis.
Endoscopy alone is not reliable for detecting the etiology of a subepithelial gastric mass. Cross-sectional imaging techniques such as transabdominal ultrasonography, computed tomography, and magnetic resonance imaging are adequate for detecting the presence of normal or abnormal structures outside the gastric wall but do not reliably distinguish between the various causes of masses arising within the gastric wall. Furthermore, when only normal structures are seen on cross-sectional imaging, it is difficult to know if the subepithelial "mass" seen on endoscopy is from external compression by a normal structure or an intramural lesion that was not seen on cross-sectional imaging. In this situation, endoscopic ultrasonography (EUS) should be performed to confirm that the subepithelial "mass" seen on endoscopy is indeed due to external compression by a normal structure and not from an intramural lesion that was not identified on cross-sectional imaging.
EUS is currently the most accurate imaging test for detecting the component of the gastric wall from which the mass arises and the echogenicity of the mass, factors that can narrow the differential diagnosis. EUS imaging alone is not sufficient to provide an accurate diagnosis of hypoechoic intramural masses, however.
Hypoechoic intramural masses are the most clinically important lesions within the gastric wall because of their malignant potential. Gastrointestinal stromal tumors, carcinoid tumors, lymphomas, and metastases from a distant primary malignancy can have significant implications for the patient and are the main reason to pursue a tissue diagnosis of this type of mass whenever possible. Submucosal masses may be amenable to endoscopic snare resection, whereas masses arising from the muscularis propria can be sampled with EUS-guided fine-needle aspiration or core biopsy. Use of immunocytochemistry is helpful in distinguishing between the potential causes of hypoechoic intramural masses. Unfortunately, the true malignant potential for individual gastrointestinal stromal tumors cannot be accurately determined using current imaging and noninvasive sampling methods.
Patients with symptoms that can be attributed to the mass should undergo endoscopic or surgical resection of the mass. Current evidence does not allow making a firm recommendation on the optimal management of the patient with an incidentally detected, asymptomatic gastric subepithelial mass. Options include performing no further testing or monitoring, following the mass with periodic endoscopic or EUS surveillance, and endoscopic or surgical resection of the mass (see table below). These management options should be discussed with the patient and whenever possible guided by EUS imaging and tissue sampling information, because the clinical significance of the mass is highly variable
Summary of The Recommendations for the Management of Asymptomatic Gastric Subepithelial Masses
| No further investigation or follow-up |
Follow with periodic endoscopy and/or endoscopic ultrasonography (EUS) or resection |
Resection |
- Normal extramural organ
- Lipoma
- Duplication cyst
- Pancreatic rest
- Inflammatory fibroid polyp
- Neural origin tumors (e.g., Schwannoma)
|
- Gastrointestinal stromal tumor <3 cm in diameter
- Glomus tumor
|
- Carcinoid in absence of hypergastrinemia
- Gastrointestinal stromal tumor ≤3 cm diameter
|
