| Backgrounds and aims:Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. They are submucosal lesion covered by the normal mucosa. The histological diagnosis is usually difficult when tissue speciemens are obtained using a standard forcep biopsy through the conventional endoscopy. The ability of endoscopic ultrasonography (EUS) to clearly demonstrate the gastric wall and its layers makes it a great tool for the clinician to make the differential diagnosis of "real" submucosal lesions. Moreover, it can also assist in their exact pathologic diagnosis by EUS-guided fine needle aspiration (EUS-FNA). Because of the potential malignant features of GISTs, surgical resection was the main treatment in the past time. With the progression of the endoscopy instruments and endoscpic operation, importantly, under the guidance of the EUS, GISTs can be removed by appropriate endoscopic treatment such as endoscopic mucosa resection (EMR), endoscopic sunmucosal dissection (ESD) without severe complications. In this study, we evaluate the role of EUS in the diagnosis and differentiation of gastric gastrointestinal stromal tumor. And also evaluate the feasibility, curative effect and safety of endoscopic treatment.Methods: 1. A total of 1163 consecutive patients with submucosal lesions in upper gastrointestinal tract found by conventional endoscope were included in EUS examination during the period from May 2004 to May 2010 in Qilu Hospital of Shandong University, China. There were 160 (13.7%) gastric stromal tumor composed of 89 males and 71 females, and aged from35 to 78 years, with a mean of 56 years.101 ectopic pancreases (8.6%) including 57 males and 44 females aged from 15 years to 72 years (mean 43 years).12 lipoma(1.0%),8 males and 4 females, aged from 27 years to 65 years, their mean age was 47 years.2. EUS examination was used to observe the location, size, layers of origin and the internal echo pattern of the stromal tumors. And furthermore differentiate from lipoma and ectopic pancrease.3.26 gastric stromal tumors with the diameter smaller than 2cm and muscularis layer origin underwent different kinds of endoscopic treanment according to the EUS findings.Results:1. Gastric stromal tumors were predominantly located in the body (46.8%) which usually originated from the fourth layer (53.1%). Gastric stromal tumors were larger than ectopic pancreas or lipomas (28.7±14.8mm vs 11.5±5.6mm or 1.34±0.38mm, p<0.05) with smooth margin (64%) and homogeneous hypoechoic (55.3%) or intermediate internal echo (42.5%). While the ectopic pancreas and lipoma mainly originated from the third layer (69.3%,75%). Lipoma shows hyperechoic (83.3%). Ectopic pancreas predominately shows intermediate inner echo (63.4%) with irregular maigin (75.2%).2. Based on EUS images, we treated 26 GISTs by different endoscopic therapies, including snare electrosection, endoloop and ESD. Complete resection of the lesions was achieved in all cases. Only two patients suffered from bleeding or resection-related perforation. All wounds were closed up nicely and no recurrence was found in the follow-up after 12 months.Conclusions: 1. Gastric stromal tumors mainly located in the body or fundus with smooth margin and homogeneous hypoechoic or intermediate inner echo. It predominately originated from the musculrus propria. Gastric stromal tumors are quite different from ectopic pancreas and lipoma on the respect of location, size, origin and inner echo pattern. So the EUS is of great value in diagnosing stromal tumors.2. Preoperative EUS examination is important for choosing the type of endoscopic therapy for stromal tumors. By which the lesions can be treated safely and effectively. |
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