医学影像英语每日学丨163.Ewing Sarcoma
每天朗读一段医学影像学英语文章
领读：Aimee老师
HISTORY
A 5-year-old boy with several months of increasing right knee pain and limping.
Frontal (A) and lateral (B) radiographs of the right tibia and fibula. An ill-defined metaphy-seal lesion is present that demonstrates mixed sclerosis and lucency at the anterior aspect of the tibia.
Unenhanced coronal T1-weighted (C) and T2-weighted (D) images of the right tibia. Abnormal low T1, high T2 marrow signal is present in the tibial metaphysis, extending into the diaphysis, with destruction of the cortex. Extraosseous tumor and edema are demonstrated on the T2-weighted image.
DIAGNOSIS
Ewing sarcoma
KEY FACTS
Ewing sarcoma can develop in almost any bone in the body, and equally affects both long and flat bones. Lesions usually occur in the midshaft of a long bone, rather than the ends as with osteosarcoma.
Plain films underestimate the extent of bone involvement. The most typical pattern is a permeative, lytic pattern with associated periosteal reaction. However, other patterns include larger, “moth-eaten” lytic foci, a mixed lytic and sclerotic pattern, bony expansion, and a predominantly sclerotic pattern.
Ewing’s sarcoma of flat bones typically has a large soft tissue component relative to the osseous component, in contrast to Ewing’s sarcoma of long bones.
MR imaging is the imaging modality of choice to determine tumor size, intra- and extraosseous extension, involvement of adjacent organs and neurovascular structures. Intravenous contrast material can be used to distinguish tumor from peritumoral edema.
MR imaging of the entire bone at the primary site of involvement is important as skip metastases occur with Ewing’s sarcoma as well as osteosarcoma.
The assessment for metastatic disease should include a chest CT to search for pulmonary metastatic disease and a bone scan for distant bony metastases.
Notes:
1. Ewing sarcoma 尤文肉瘤
sarcoma [sɑ:rˈkoʊmə] n. 肉瘤
2. osteosarcoma [ˌɒsti:oʊsɑ:'koʊmə] n. 骨肉瘤
3. lytic ['lɪtɪk] adj. 细胞溶解酶的
4. periosteal [pɪəri:oʊs'tel] 骨膜的
5. moth-eaten 虫蚀样
6. sclerotic [sklə'rɒtɪk] adj. 硬化的
7. osseous [ˈɑ:siəs] adj. 骨的
8. edema [ɪ'di:mə] n. 水肿
9. metastatic [ˌmetə'stætɪk] adj. 转移性的
【Ewing Sarcoma 尤因/尤文氏肉瘤】
病史：男，5岁，右膝疼痛加剧数月、跛行
在右侧胫腓骨正侧位平片上，可见干骺端有一边界不规则病变，胫骨前缘硬化型和溶骨型病变共存。
冠状位T1和T2平扫可见胫骨干骺端处T1低，T2高的异常骨髓信号，侵犯骨干，破坏骨皮质。T2上可见骨外瘤样病变和水肿。
诊断：尤文肉瘤
关键点：尤文肉瘤几乎可以累及全身各部位的骨，长骨、扁骨受累几率相同。病灶好发于长骨中段，不同于骨肉瘤，常位于末端。
平片常不能完全显示病变的范围。最常见的类型是浸润的溶骨性病变，伴骨膜反应。其他类型也包括：巨大型、虫蚀样溶骨型、硬化和溶骨混合型、膨胀型和硬化为主型。
扁骨的尤文肉瘤典型表现为，软组织成分对于骨的成分，有别于长骨的尤文肉瘤。
MR是判断肿瘤大小、骨内外浸润、邻近器官和血管受累情况的最佳检查方法。静脉内注入对比剂有助于鉴别肿瘤和肿瘤周围的水肿。
在MRI上寻找病变的原发灶很重要，因为同骨肉瘤一样，尤文肉瘤也会发生跳跃性转移。
对于转移的评估，应行胸部CT看是否存在肺部转移，行骨扫描看远端骨转移情况。
来源：每天朗读一段医学影像学英语文章
圈主
深圳市人民医院放射科副主任医师杨敏洁