胃及十二指肠恶性间质瘤的影像诊断

Malignant gastroduodenal stromal tumor imaging diagnosis

目的探讨胃及十二指肠恶性间质瘤的X线造影和CT影像表现,旨在提高对该病的认识。方法回顾分析经病理和免疫组化证实的24例(mGDST)资料。术前均行CT平扫和三期增强扫描,其中15例同时行上消化道气钡双重造影。分别采用双盲阅片分析肿瘤的部位、大小、形态、边缘、生长方式、黏膜表面溃疡情况及CT增强模式等影像表现。结果 mGDST发生在胃底贲门部15例,胃体3例,胃窦2例,十二指肠4例。病变主要分为3种类型:黏膜下型9例,肌壁间型9例,浆膜下型6例,肿瘤最大径>5cm有14例、分叶17例、有坏死15例,黏膜破坏及溃疡形成6例、不均匀强化14例,转移1例,X线造影和CT检查的定位正确率分别为93.3%、100%,综合两种检查的定性诊断准确性为75.0%(18)。结论 mGDST具有一定影像特征,表现为病灶体积较大、有分叶、中心坏死、黏膜破坏及溃疡形成、不均匀强化、转移等,淋巴结肿大少见。CT结合钡餐可提高mGDST判断正确率,具有较高的临床指导意义。

Objective To assess the imaging features of malignant gastroduodenal stromal tumor （mGDST）as an aid to its diagnosis. Methods The unenhanced and multi-phasic contrast-enhanced CT scans of 24 patients with pathologically proven mGDST and air-contrast upper gastrointestinal studies（15 patients） were reviewed by two radiologists. The tumor location, size, contour, margin, growth type, contrast enhancement pattern and presence of ulcer were recorded. Results The mGDST was located in the gastric fundus （15）, gastric body（3）, pylorus（2） and duodenum（4）. The pathological types were submucosal（9）, intramuscular（9） and subserosal（6）. CT findings of mGDST included lobular shape（17）, tumor size〉5cm（14）, central necrosis（15）, large and deep ulcer（6）, heterogeneous contrast enhancement（1）, metastasis（1）. The diagnostic accuracy of air-contrast upper gastrointestinal studies and CT for location of mGDST was 93.3% and 100% respectively, for malignant features was both 75.0%. Conclusion Most mGDST have some characteristic appearances including large tumor size greater than 5cm, lobular shape, central necrosis, large and deep ulcer, heterogeneous contrast enhancement and metastasis. Lymph node enlargement was uncommon. The diagnostic accuracy can be improved by CT scan combined with upper gastrointestinal barium examination.