imaging of the suprahyoid neck - unc radiology · spaces of the suprahyoid neck •parapharyngeal...
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Imaging of the Suprahyoid
Neck
Benjamin Y. Huang, MD, MPH
Department of Radiology
University of North Carolina School of
Medicine
Neck Overview
• 2 distinct anatomic regions
– Suprahyoid
– Infrahyoid
• Both regions further subdivided into
multiple fascia lined spaces
• Spatial approach is useful for nonmucosal
(deep) H&N lesions
The Deep Cervical Fascia
3 Layers of DCF
• Superficial(investing; SL-DCF)
• Middle(buccopharyngeal; ML-DCF)
• Deep (prevertebral; DL-DCF)
Spaces of the Suprahyoid Neck
• Parapharyngeal (PPS)
• Pharyngeal Mucosal (PMS)
• Masticator (MS)
• Parotid (PS)
• Carotid (CS)
• Retropharyngeal (RPS)
• Perivertebral space (PVS)
Parapharyngeal Space
• Extends from skull base to SMS
• Not truly fascially enclosed
• Borders all three layers of DCF
• Openly communicates with SMS
Parapharyngeal Space
Contents
• Fat
• Minor salivary
glands
• Internal maxillary a.
• Ascending
pharyngeal a.
• Pterygoid venous
plexus
Parapharyngeal Space
PPSPPS
T1W MRICE CT
Parapharyngeal Space
• Primary PPS lesions rare
– BMT
– Minor salivary tumors
– Lipoma
– Atypical branchial cleft cysts
• PPS displacement pattern is key to defining site of origin of other deep neck masses!
Pharyngeal Mucosal Space
• Continuous mucosal sheet from NP to HP (including soft palate)
• Bordered posteriorly and laterally by ML-DCF
• Superiorly bordered by basisphenoid & basiocciput (including foramen lacerum)
Pharyngeal Mucosal Space
Contents
• Pharyngeal mucosa
• Waldeyer’s ring
• Minor salivary glands
• Pharyngobasilar fascia
• Pharyngeal constrictor mm.
• Levator palatini m.
• Torus tubarius
Pharyngeal Mucosal Space
Pharyngeal Mucosal Space
Lesions• PMS lesions push
PPS fat laterally
• DDxMucosa
– SCC
Lymphoid
– NHL
Minor salivary gland
– MSG tumor
Muscle
– Rhabdomyosarcoma
Masticator Space
• Enclosed by SL-DCF
• Extends from high parietal calvarium to mandibular angle
• Abuts skull base (including foramen ovale & spinosum)
Masticator Space
Contents
• Musles of mastication
• CN V3
• Ramus & posterior body of mandible
• Pterygoid venous plexus
Masticator Space
Masticator Space Lesions
• MS lesions push PPS fat posteromedially
• DDxMuscle
– Sarcoma
Mandible
– Sarcoma
– Osteo/chondrosarcoma
– Mets/Myeloma
Nerve
– Nerve sheath tumor
Vascular
– Hemangioma
– Lymphangioma
Other
– Lymphoma/leukemia
– SCC (from the RMT)
Parotid Space
• Enclosed by SL-
DCF
• Extends from skull
base/EAC to below
mandibular angle
Parotid Space
Contents
• Parotid gland/duct
• Facial nerve
• ECA
• Retromandibular v.
• Intraparotid nodes
• Accessory parotid tissue
Parotid Space
Parotid Space Lesions
• PS lesions push PPS fat medially
• DDxParotid
– BMT
– Salivary gland malignancies
– Warthin’s tumors
– Lymphoepithelial cysts
Nerve
– Schwannoma
Lymph Node
– Lymphoma
– Nodal metastases
– Reactive nodes
Vascular
– Hemangioma/Lymphangioma
Other
– 1st branchial cleft cyst
Carotid Space
• Aka post-styloid PPS
• Extends from skull base (jugular foramen & carotid canal) to aortic arch
• All 3 layers of DCF contribute to carotid sheath
Carotid Space
Contents
Suprahyoid
• ICA
• IJV
• CN 9-12
• Sympathetic plexus
• Lymph Nodes
Infrahyoid
• CCA
• IJV
• CN 10
• Lymph Nodes
Carotid Space
Carotid Space Lesions
• CS lesions push PPS fat anteriorly
• DDxNerves/Plexus
– Paraganglioma
– Schwannoma
Vascular
– IJV thrombosis
– CA aneurysm
– CA dissection
Lymph Nodes
Retropharyngeal Space
• Fat filled space posterior posterior to pharynx & trachea
• Enclosed by ML- & DL-DCF
• Separated from DS by slip of DL-DCF
• Extends from skull base to mediastinum (T3)
Retropharyngeal Space
Contents
• Fat
• Lymph nodes (SH
neck only)
– Medial
– Lateral (Rouviere)
Retropharyngeal Space Lesions
• Lateral - displace CS laterally and PPS anterolaterally
• Medial - flatten the prevertebral mm and displace the PMS anteriorly
• DDXNodes
– SCC/NPC mets
– Lymphoma
– Reactive/Suppurative
Fat
– Lipoma
Other
– Abscess/cellulitis
– Effusion/edema
Perivertebral Space
• Space surrounding the
vertebral column
extending from skull
base to upper
mediastinum
• Bounded by DL-DCF
• 2 major components
– Prevertebral
– Paraspinal
Perivertebral Space
Contents
• Prevertebral– Prevertebral mm.
– Scalene mm.
– Brachial plexus roots
– Phrenic nerve
– Vertebral a. & v.
– Vertebral body
• Paraspinal– Posterior elements
– Paraspinal mm.
Perivertebral Space Lesions
• Prevertebral
lesions lift the
prevertebral mm.
off the spine
• Primary paraspinal
masses push the
posterior cervical
fat laterally
Perivertebral Space Lesions
• DDx
Spine– Tumor (Met, sarcoma,
chordoma, B9)
– Discitis/osteomyelitis
Muscle– Sarcoma
– Lymphoma
– Pseudomass (hypertrophy)
Nerve– Schwannoma/NF
Other Spaces
• Buccal space
• Floor of mouth
– Sublingual
space
– Submandibular
space
• Posterior
cervical space
SAMPLE
CASES
SCC – Oropharynx
PMS
High Grade Mucoepidermoid Ca
PS
Ewing Sarcoma
Masticator
Space
Glomus Vagale
CS
Pleomorphic Adenoma
PS
Retropharyngeal
Effusion/Abscess
RPS
Chloroma
MS
Schwannoma
CS
Case courtesy of
Dr. Craig Harr
RP Nodal Met – NP Ca
Summary
• Deep neck can be compartmentalized
based on DCF planes
• Identifying the space of origin can help
pare down DDx
• Look at the PPS displacement to help
identify the space of origin