胃肠道间质瘤的CT诊断

目的：分析胃肠道间质瘤（GIST）的CT表现特点，探讨CT对该肿瘤的诊断价值。资料与方法：回顾性分析经手术病理证实的GIST21例，术前均行CT平扫和增强扫描。结果：肿瘤发生于胃部11例，十二指肠1例，空肠5例，回肠4例，病灶多呈圆形或类圆形，平扫：肿瘤呈均匀等密度者8例，肿块周边呈等密度，中间呈略低密度或低密度者12例，呈高，等，低混杂密度者1例，增强扫描：病灶中度或明显强化者10例；不均匀强化，其内可见多数小囊状坏死者5例，病灶中央坏死，液化，周边强化者6例，21例GIST中，良性7例，肿块直径多小于5cm，边界清楚，多均匀强化，恶性14例，肿块直径大于5cm,边界多不清楚，10例肿块内有坏死，5例出现转移灶。结论：CT检查对于GIST的定位准确，对肿瘤良恶性的判断亦很有价值，但CT表现无特异性，确诊仍有赖于病理学检查。

CT Diagnosis of Gastrointestinal Stromal Tumors

Objective To analyze CT features of gastrointestinal stromal tumors (GIST) and to evaluate CT in the diagnosis of the disease.Materials and Methods Both plain and enhanced CT findings in 21 cases with pathologically proved GIST were retrospectively analyzed.Results The tumors originated from the stomach (n=11), duodenum (n=1), jejunum (n=5) or ileum (n=4). The lesions were mainly round or oval in shape. On plain CT scans, the tumors showed homogeneous isodensity (n=8), or low density centrally with isodensity peripherally (n=12), or mixed density (n=1). On enhanced CT scans, moderate or marked enhancement was seen in 10 cases, heterogeneous enhancement with small cystic necrosis in 5, and central necrosis with peripheral enhancement in 7. Of 21 GIST, 7 were benign and 14 were malignant. The benign lesions were usually below 5 cm in size with well defined margin and displayed homogeneous enhancement. The malignant lesions were ill defined and over 5 cm in size, with necrosis within the tumor (n=10) or metastases (n=5).Conclusion CT can precisely localize GIST and is also very helpful in differentiating benign with malignant GIST, although it is difficult to differentiate from leiomyoma or leiomyosarcoma as GIST shows no characteristic CT signs, therefore, a confirmed diagnosis relies on the pathological examination.