Cory D A, Cohen M D, Smith J A
Radiology. 1987 Feb;162(2):457-9. doi: 10.1148/radiology.162.2.3797659.
A soft-tissue nodule was identified in the mediastinum superior to the left brachiocephalic vein in six patients undergoing computed tomography (CT) of the chest. In one case, biopsy of the mass showed that it was thymic tissue. In the remaining cases, the nodule was identified as thymus on the basis of the CT findings. The findings include equal density of the superior mediastinal nodule and the thymic lobes anterior to the ascending aorta, no displacement or narrowing of adjacent arteries, absence of a fat plane between the nodule and the thymic lobes, and parallel reduction in size of the nodule and the rest of the thymus. Two patients were examined with magnetic resonance (MR) imaging. Sagittal MR images demonstrated continuity of the superior mediastinal nodule with the more caudal portion of the thymus. Recognition of this normal variant in children is important in order to avoid unnecessary mediastinal biopsies or overstaging of malignancies.
在6例接受胸部计算机断层扫描（CT）的患者中，在左头臂静脉上方的纵隔内发现了一个软组织结节。在1例中，对该肿块进行活检显示为胸腺组织。在其余病例中，根据CT表现将结节确定为胸腺。这些表现包括上纵隔结节与升主动脉前方的胸腺叶密度相等，相邻动脉无移位或变窄，结节与胸腺叶之间无脂肪平面，以及结节与胸腺其余部分大小平行减小。对2例患者进行了磁共振（MR）成像检查。矢状面MR图像显示上纵隔结节与胸腺更靠尾侧的部分连续。认识到儿童中的这种正常变异对于避免不必要的纵隔活检或恶性肿瘤的过度分期很重要。
