Retropharyngeal lymph nodes
Located in the retropharyngeal space between the visceral (buccopharyngeal) fascia and the alar fascia, there are two groups 1:
- medial retropharyngeal lymph nodes
- located near the midline immediately anterior to the prevertebral muscles
- less common: visible on imaging in only a minority of children and rarely present in adults 2; usually unilateral
- usually located at the C2-C3 level
- lateral retropharyngeal lymph nodes
- immediately anterior to the lateral margins of the prevertebral muscles
- more common: found in the vast majority of children and most adults; usually bilateral
- usually located more superiorly, at the skull base (C1) or C1-C2 level
The node of Rouviere refers to the superiormost lateral retropharyngeal lymph node, although the term "nodes of Rouviere" has also been used to refer to the lateral retropharyngeal lymph node group in general.
The retropharyngeal lymph nodes decrease in size and number with age 3. In one study of healthy subjects using MRI, the upper limit of normal (2 standard deviations above the mean) of minimal axial diameter of lateral retropharyngeal lymph nodes was 9 mm in children (6-19 years), 6.4 mm in young and middle aged adults (20-38 years), and 5.2 mm in older adults (42-74 years).
Etymology and history
The existence of retropharyngeal lymph nodes was first described by Henri Rouvière in 1928 4.
Metastatic lymphadenopathy, such as from nasopharyngeal carcinoma, may be suggested on imaging in older adults by the presence of retropharyngeal nodes with a minimal axial diameter larger than 6 mm, centrally necrotic nodes, ipsilateral grouping of two or more nodes, or presence of medial group nodes 5.
They may be mimicked by the superior cervical ganglia, which are nodular structures located slightly more posterolaterally than lateral retropharyngeal lymph nodes, anterior to the C2 transverse process and immediately medial or anteromedial to the internal carotid artery 6.
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- 2. Ozlugedik S, Ibrahim Acar H, Apaydin N, Firat Esmer A, Tekdemir I, Elhan A, Ozcan M. Retropharyngeal space and lymph nodes: an anatomical guide for surgical dissection. (2005) Acta oto-laryngologica. 125 (10): 1111-5. doi:10.1080/00016480510035421 - Pubmed
- 3. Ogura I, Kaneda T, Kato M, Mori S, Motohashi J, Lee K. MR study of lateral retropharyngeal lymph nodes at different ages. (2004) Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 98 (3): 355-8. doi:10.1016/S107921040400441X - Pubmed
- 4. Rouviere H. Anatomy of the Human Lymphatic System: A Compendium. (1938). ISBN: 0598832173.
- 5. Zhang GY, Liu LZ, Wei WH, Deng YM, Li YZ, Liu XW. Radiologic criteria of retropharyngeal lymph node metastasis in nasopharyngeal carcinoma treated with radiation therapy. (2010) Radiology. 255 (2): 605-12. doi:10.1148/radiol.10090289 - Pubmed
- 6. Yokota H, Mukai H, Hattori S, Yamada K, Anzai Y, Uno T. MR Imaging of the Superior Cervical Ganglion and Inferior Ganglion of the Vagus Nerve: Structures That Can Mimic Pathologic Retropharyngeal Lymph Nodes. (2018) AJNR. American Journal of Neuroradiology. 39 (1): 170-176. doi:10.3174/ajnr.A5434 - Pubmed