Shirakura Satoshi, Tsunoda Atsunobu, Akita Keiichi, Sumi Takuro, Suzuki Masami, Sugimoto Taro, Kishimoto Seiji
Department of Head & Neck Surgery, Tokyo Medical and Dental University, Japan.
Auris Nasus Larynx. 2010 Oct;37(5):621-5. doi: 10.1016/j.anl.2010.01.003. Epub 2010 Feb 24.
The parapharyngeal space (PS) is defined as the deepest space in the neck and it consists of the pre- and post-styloid regions. PS tumors originating in these regions are thought to dislocate the carotid artery (CA) in either the posterior or anterior direction. To determine the precise anatomy of the PS and its relationship with the CA in diagnostic images, we conducted cadaveric and imagining analysis.
We examined the posterior and lateral aspects of the PS in three cadavers. We also examined 17 patients who suffered from PS tumors, in which the carotid artery was dislocated (CA), then compared the results with surgical and pathological findings.
The anterior part of the PS was mainly composed of fatty tissue and is generally referred to as the pre-styloid region of the PS. In the posterior of this fatty region, blood vessels and nerves were tightly covered with muscles and adjacent fascias to form a compact musculo-fascial structure containing the CA, jugular vein, vagal, glossopharyngeal, accessory and sympathetic nerves, and a portion of the hypoglossal nerves. The hypoglossal nerves emerged from the hypoglossal canal posterior to this structure and coursed behind it, entering it at the upper third of the PS. These anatomical findings indicated that the PS was actually comprises of three regions. Image analysis showed that the CA was dislocated in the postero-lateral direction by a pleomorphic adenoma originating from the parotid gland and by a trigeminal schwannoma, both of which were pre-styloid tumors. On the other hand, the post-styloid tumors did not always dislocate the CA in the anterior direction. Tumors that developed within the musculo-fascial structure such as those of the carotid body tumor or sympathetic nerve schwannoma dislocated the CA from both the antero- to the postero-lateral directions. A hypoglossal nerve schwannoma originating from the most posterior part of the PS, which was behind the musculo-fascial structure dislocated the CA in the anterior direction.
The present findings indicated that the post-styloid region of the PS is considered to consist of two regions. As the CA is a component of this musculo-fascial structure, tumors originating from it that are defined as post-styloid did not always displace the CA in the anterior direction. Such anatomical recognition is helpful for diagnostic imaging of PS tumors.
咽旁间隙（PS）被定义为颈部最深的间隙，它由茎突前和茎突后区域组成。起源于这些区域的PS肿瘤被认为会使颈动脉（CA）向后或向前移位。为了在诊断图像中确定PS的精确解剖结构及其与CA的关系，我们进行了尸体解剖和影像学分析。
我们检查了三具尸体的PS的后部和外侧。我们还检查了17例患有PS肿瘤且颈动脉移位（CA）的患者，然后将结果与手术和病理结果进行比较。
PS的前部主要由脂肪组织组成，通常被称为PS的茎突前区域。在该脂肪区域的后部，血管和神经被肌肉和相邻的筋膜紧密覆盖，形成一个紧凑的肌筋膜结构，其中包含CA、颈静脉、迷走神经、舌咽神经、副神经和交感神经，以及一部分舌下神经。舌下神经从该结构后方的舌下神经管穿出，并在其后方走行，在PS的上三分之一处进入该结构。这些解剖学发现表明PS实际上由三个区域组成。图像分析显示，起源于腮腺的多形性腺瘤和三叉神经鞘瘤（均为茎突前肿瘤）使CA向后外侧方向移位。另一方面，茎突后肿瘤并不总是使CA向前方移位。在肌筋膜结构内发生的肿瘤，如颈动脉体瘤或交感神经鞘瘤，使CA从前后外侧方向移位。起源于PS最后部（位于肌筋膜结构后方）的舌下神经鞘瘤使CA向前方移位。
目前的研究结果表明，PS的茎突后区域被认为由两个区域组成。由于CA是该肌筋膜结构的一个组成部分，起源于该区域（被定义为茎突后）的肿瘤并不总是使CA向前方移位。这种解剖学认识有助于PS肿瘤的诊断性影像学检查。
