Weber A L, Liebsch N J, Sanchez R, Sweriduk S T
Department of Radiology, Harvard Medical School, Boston.
Neuroimaging Clin N Am. 1994 Aug;4(3):515-27.
Chordomas are uncommon skull base tumors, which are locally agressive and are usually not amenable to complete surgical resection. Proton beam irradiation, following surgery, is the preferred treatment modality. For diagnosis and determination of tumor site and extension, CT and MR imaging are the imaging modalities of choice. CT delineates bone destruction and the presence of calcifications and destroyed bone optimally. MR imaging is the modality of choice for better definition of the tumor margin from brain and other soft tissue structures (pharynx) and visualization of blood vessels. The signal intensities and enhancement pattern fail to differentiate chordoma from chondroid chordoma or chondrosarcoma. Chordomas arise from the clivus and therefore are located more centrally, whereas the majority of chondrosarcomas originate in the petroclival fissure and occur more laterally, although occasional overlap occurs in about one third of cases. Immunohistochemical methods allow differentiation of pure chordoma from chondroid chordoma and chondrosarcoma. Chordomas have a lower local control rate than chondrosarcomas.
脊索瘤是一种罕见的颅底肿瘤，具有局部侵袭性，通常无法通过手术完全切除。手术后质子束照射是首选的治疗方式。对于诊断以及肿瘤部位和范围的确定，CT和磁共振成像（MR成像）是首选的成像方式。CT能最佳地描绘骨质破坏以及钙化和骨质破坏的情况。MR成像则是用于更好地界定肿瘤与脑及其他软组织结构（咽）边界以及观察血管的首选方式。信号强度和强化模式无法区分脊索瘤与软骨样脊索瘤或软骨肉瘤。脊索瘤起源于斜坡，因此位置更靠中心，而大多数软骨肉瘤起源于岩斜裂，位置更偏外侧，不过约三分之一的病例会出现两者位置偶尔重叠的情况。免疫组织化学方法可区分纯脊索瘤与软骨样脊索瘤及软骨肉瘤。脊索瘤的局部控制率低于软骨肉瘤。
