Infrahyoid Neck

Question 1

What are the spaces of the infra hyoid neck?

Answer 1

1. Visceral
2. Carotid
3. Retropharyngeal
4. Posterior cervical
5. Perivertebral

Question 2

What is the visceral space?

Answer 2

Central compartment containing several viscera: larynx, thyroid, hypo pharynx and cervical oesophagus.
Extends from hyoid to mediastinum; no supra hyoid extension.

Question 3

What is the carotid space?

Answer 3

Paired space just lateral to the visceral compartment. Contains CCA, ICA, IJV, vagus.

Question 4

What is the retropharyngeal space?

Answer 4

Small virtual space containing only fat; continuous with the supra hyoid space and the middle mediastinum

Question 5

What is the posterior cervical space?

Answer 5

Paired space posterolateral to the carotid space

Question 6

What is the perivertebral space?

Answer 6

large space completely encircling vertebral body, including pre and paravertebral muscles.

Question 7

What is the approach to pathology in the infra hyoid neck?

Answer 7

1: Which space is lesion?
2: what is normally in this space?
3. What pathology arises from normal contents? Does it fit clinical picture?

Question 8

What are the strap muscles?

Answer 8

TOSS:

• thyrohyoid
• omohyoid
• sternohyoid
• sternothyroid

Question 9

What is the role of the strap muscles?

Answer 9

All connected to hyoid and depress hyoid bone and larynx during swallowing and speaking

Question 10

Ddx of lesion in supraglottic larynx?

Answer 10

• Mucosal: squamous Ca
• Submucosal:
• -laryngocele
• -chondrosarcoma
• -paraganglioma
• -schwannoma

Question 11

Pathology of hypopharynx / oesophagus?

Answer 11

• Zenker’s diverticulum

- squamous cell Ca

Question 12

Pathology of trachea?

Answer 12

• carcinoma

- benign stenosis

Question 13

Pathology of thyroid?

Answer 13

• Goitre
• colloid cyst
• carcinoma (papillary, follicular, anaplastic)
• Hashimoto’s

Question 14

Pathology of parathyroid?

Answer 14

• Adenoma

- Hyperplasia

Question 15

Embryological remnants which may be found in visceral space?

Answer 15

• Thyroglossal duct

- 3rd branchial cyst

Question 16

How to distinguish paratracheal LNs from thyroid (e.g. tmng) on imaging?

Answer 16

LNs lie outside strap musculature

Question 17

Where does the thyroglossal duct run?

Answer 17

From the base of tongue at foramen caecum to the thyroid gland

Question 18

What is a thyroglossal duct cyst?

Answer 18

Persistence of thyroglossal duct enables development of cyst

Question 19

DDx thyroglossal duct cyst?

Answer 19

• necrotic anterior cervical nodes

- thrombosed jugular vein

Question 20

What is important to check on identification of thyroglossal duct cyst?

Answer 20

Thyroid is in normal position:

• thyroid anlage may never travel along duct
• remains at tongue base
• =lingual thyroid

Question 21

Where does the carotid space extend?

Answer 21

Skull base to aortic arch

Question 22

Contents (real and potential) of carotid space?

Answer 22

• carotid artery
• IVJ
• CNX
• Sympathetic plexus
• LNs (level 2-4)
• Congenital remnants of 2nd branchial cleft

Question 23

Pathology of CCAs?

Answer 23

• Dissection
• Thrombosis
• Aneurysm

Question 24

Pathology of IJV?

Answer 24

• Thrombosis

- Thrombophlebitis

Question 25

Pathology of CNX?

Answer 25

- Schwanomma | - Neurofibroma

Question 26

Pathology of sympathetic plexus?

Answer 26

-paraganglioma

Question 27

Pathology of LNs of carotid space?

Answer 27

- Lymphoma | - Squamous/thyroid Ca mets

Question 28

Congenital remnant pathology of carotid space?

Answer 28

Second branchial cleft cyst

Question 29

Key features of a paraganglioma?

Answer 29

- aka carotid body tumor. - Multiple in 4% of patients. - 25% have a positive family history. - Intense enhancement on CT and MR. - Flow voids are frequently present.

Question 30

How may the retropharyngeal space become infected?

Answer 30

1. Classic: paeds ==> URTI spreads to retropharyngeal LNs | 2. Penetrating trauma: FBs (fish bones) or iatrogenic (intubation)

Question 31

Contents of posterior cervical space and pathology potential?

Answer 31

- fat (lipoma) - CNXI (schwannoma, neurofibroma, MPNST) - Brach Plex (as above + apical lung / breast Ca, lymphoma) - LNs: lymphoma mets, TB

Question 32

MPNST?

Answer 32

malignant peripheral nerve sheath tumour

Question 33

Development pathology of posterior cervical space?

Answer 33

- primitive embryonic lymph sacs (cystic hygroma, lymphangioma) - 3rd branchial cleft (cyst)

Question 34

Homogenous enhancement of LNs suggestive of?

Answer 34

Lymphoma

Question 35

What is lymphangioma?

Answer 35

- Benign non-capsulated lesion arising from expanding embryonic lymph 'lakes' that do not develop normal lymphatic drainage. - 90% in children 10% in young adults. - occur anywhere in the head and neck; mostly in posterior cervical space. -10% extend into the mediastinum. - High signal on T2-weighted images - Signal on T1-weighted images depends on protein content. - Hemorrhage results in rapid growth and fluid-fluid levels as seen on MR

Question 36

Contents and perivertebral space and potential path?

Answer 36

- 1. Vertebra (osteomyelitis, 1/met bone Ca) - 2. Muscles (myositis, abscess, sarcoma, fibromatosis) - 3. BPlex: schwanomma, neurofibroma, MPNST - 4. Vert art/vein: aneurysm, dissection, thrombosis