[Endoscopic, clinicopathologic and immunohistochemical features of gastric stromal tumor].

Background & Objective: For gastric stromal tumor (GST), the low incidence and high diversity in endoscopic and pathologic manifestations lead to misdiagnosis. This study was to explore the features of GST in endoscopy and clinicopathology.

Methods: Clinical data of 42 GST patients, treated at the Second Affiliated Hospital of Sun Yat-sen University from Jan. 1996 to Jan. 2006, were analyzed for their clinicopathologic and endoscopic features. The expression of CD117, CD34, smooth muscle actin (SMA), Desmin and S-100 were detected by immunohistochemistry. Their correlations to clinicopathologic features of GST were analyzed.

Results: Of the 42 cases of GST, 21 (50.0%) were at the fundus, 14 (33.3%) at the body, and 7 (16.7%) at the antrum; 17 (40.5%) were benign, 14 (33.3%) borderline, 11 (26.2%) malignant. Endoscopically, GST presented submucosal hemispheroid or polypoid protuberant lesions with clear border. While the positive rate of gastroendoscopic biopsy was low. Of the 42 cases, 29 were spindle cell type, 5 were epithelial cell type, and 8 were mixed type. The positive rates of CD34 and CD117 were 92.86% and 78.57%.

Conclusions: GST has unique morphologic features. Combined detection of CD117 and CD34 benefits the diagnosis of GST.