Weber A L, Brown E W, Hug E B, Liebsch N J
Massachusetts Eye and Ear Infirmary, Boston, USA.
Otolaryngol Clin North Am. 1995 Jun;28(3):453-71.
Chordomas and chondrosarcomas are uncommon skull base tumors. They are locally aggressive. Chordomas arise from the clivus with the epicenter in the midline of the skull base. Chondrosarcomas, in contrast, usually arise along the petro-occipital fissure; occasionally, a chondrosarcoma may reveal a midline location and then cannot be differentiated from chordoma. Chordomas rarely calcify, whereas calcification is not an uncommon finding in chondrosarcomas. Following radiation, calcifications also increase in area and diameter in both chondrosarcomas. Both chondrosarcomas and chordomas reveal a low signal intensity on T1-weighted MR images and medium to increased signal intensity on T2-weighted images. They commonly enhance significantly but heterogeneously, because of the presence of necrosis, calcification, and mucinous materials. Occasionally, chondrosarcomas and chordomas reveal a low degree if enhancement. The prognoses of chordomas and chondrosarcomas vary. Long-term survival is usually seen with chondrosarcomas but is still considerably compromised with chordomas.
脊索瘤和软骨肉瘤是罕见的颅底肿瘤。它们具有局部侵袭性。脊索瘤起源于斜坡，震中位于颅底中线。相比之下，软骨肉瘤通常沿岩枕裂发生；偶尔，软骨肉瘤可能显示中线位置，此时无法与脊索瘤区分。脊索瘤很少钙化，而钙化在软骨肉瘤中并非罕见表现。放疗后，软骨肉瘤的钙化面积和直径也会增加。软骨肉瘤和脊索瘤在T1加权磁共振图像上均显示低信号强度，在T2加权图像上显示中等至增强信号强度。由于存在坏死、钙化和黏液物质，它们通常显著但不均匀强化。偶尔，软骨肉瘤和脊索瘤显示低度强化。脊索瘤和软骨肉瘤的预后各不相同。软骨肉瘤通常可长期存活，但脊索瘤的长期存活情况仍相当差。
