Background and purpose: Many reports have confirmed that endoscopic ultrasonography (EUS) can differentiate gastric submucosal tumor from extragastric compression, but only a few specifically concentrated on EUS in identifying the causes of external compression.
Materials and methods: From May 1993 to May 2001, we used EUS in 238 patients to diagnose gastric submucosal tumor or external compression. We excluded 183 patients who had submucosal tumors and analyzed the remaining 55 patients with extragastric compression. Malignant causes of external compression were proved by surgery or biopsy. Benign causes of external compression were proved by other imaging examinations (abdominal ultrasound, computerized tomography, angiography) or surgery. Patients with external compression caused by normal organs were followed up with repeated upper gastrointestinal endoscopy or EUS.
Results: The stomach was compressed by normal extragastric organs in 32 patients (spleen 10, splenic vessel 6, gall bladder 9, liver 3, pancreas 3, and intestine 1), by benign pathologic lesions in 12 patients (liver cyst 7, liver hemagioma 2, splenic cyst 1, pancreatic cyst 1, pancreatic cystadenoma 1) and by malignant tumors in 5 patients (hepatoma 1, liver metastasis from colon cancer 2, pancreatic cystadenocarcinoma 1 and lymphoma of spleen 1). In the remaining six patients, neither submucosal tumor nor external compression was found during EUS examination and the external compression was considered transient.
Conclusion: When an extragastric compression mimicking submucosal tumor is detected by upper gastrointestinal endoscopy, EUS is indicated to identify the cause of extragastric compression.