CT・MRIによる副咽頭間隙腫瘍の診断

腫瘍発生間隙の重要性

抄録

It is important to localize a lesion to one fascially-defined space because the components of each space are fairly specific, for example, the parotid space contains mainly the parotid gland, and the carotid space mainly several blood vessels and nerves. Therefore, specific tumors tend to originate in specific spaces. The CT and MRI appearance of 30 parapharyngeal tumors (12 males and 18 females; average age 50.5 years) treated at Tokyo university Branch Hospital and several affiliated hospitals were reviewed. Deviated pattern of internal carotid artery (ICA), parapharyngeal space fat (FAT), styloid process (SP) and muscles attached to the SP were compared between parotid space tumors and carotid space tumors. In most parotid space tumors, ICA was displaced posteriorly or not displaced, FAT was displaced medially, and SP was located posterior to the tumor in axial views. On the other hand, in most carotid space tumors, anterior displacement of ICA and FAT and anterior location of SP were seen in axial views. In coronal views of parotid space tumors, ICA was displaced medially or not displaced, and FAT was located between the parotid gland and the tumor. In carotid space tumors ICA was displaced in various directions, and FAT was located between the parotid gland and the tumor. The pattern of displacement of salivary gland tumors was correlated well with that of parotid space tumors, and that of neurogenic tumors correlated well with that of carotid space tumors. Thus, analysis of the displacement pattern seen in CT or MRI contributes to the diagnosis of the pathologic nature of parapharyngeal tumors