Head and Neck

Question 1

What is the aetiology of a thyroglossal cyst?

Answer 1

The cyst forms due to failure of closure of the thyroglossal duct extending from the foramen cecum (junction between anterior 2/3 and posterior 1/3 of tongue) to the thyroid gland - passes through the hyoid bone.

Question 2

What is the anatomy and aetiology of a Zenker’s diverticulum

Answer 2

Killian’s triangle is between oblique fibers of the thyropharyngeus, and horizontal fibers of the cricopharyngeus muscle (both of which make up the inferior constrictor)

Discordinated relaxation between the pharyngeus muscles and cricopharyngeus results in a pulsion diverticulum.

Question 3

What imaging would you do for a thyroglossal cyst?

Answer 3

USS
- to image cyst and also confirm presence of a thyroid gland (as can be absent)

Question 4

What are thyroglossal cysts removed?

Answer 4

Risk of infection (high)
Risk of malignancy - 1% risk of papillary thyroid cancer

Question 5

What is the aetiology of a branchial cyst?

Answer 5

Normally - the 2nd pharyngeal arch overgrows distally to cover the 2nd, 3rd, and 4th brancial clefts.

Buried clefts become ectoderm lined cavities that normally involute by the 7th week gestation.

Question 6

What is the location and path of a first branchial cyst?

Answer 6

Work type I - pre-auricular sinus which tracks to the external auditory meatus.

Work type II - found at the angle of the mandible - tracks to the external auditory meatus.

Question 7

What is the location and path of the second branchial cyst?

Answer 7

Punctum is located anterior to SCM
The fistula passes deep to the internal and external carotid arteries, and then around the hypoglossal and glossopharyngeal nerve, to enter the palatine tonsillar fossa

“between two arteries and around two nerves”

Question 8

What is the location and path of a third branchial cyst?

Answer 8

Punctum is located anterior to SCM on the middle to lower 1/3. Passes around internal and external carotid and then between hypoglossal and glossopharyngeal nerve, to enter the piriform recess of the larynx

Question 9

What are the consequences of damaging the lingual nerve during submandibular duct excision?

Answer 9

Altered salivary secretion
Altered taste to anterior 2/3 of tongue.
Sensory change to anterior 2/3 of tongue

Question 10

What are the consequences of damaging the hypoglossal nerve during submandibular duct excision?

Answer 10

Loss of motor innervation to all intrinsic muscles of the tongue except palatoglossus
o Ipsilateral tongue weakness and deviation.
o Dysarthria and dysphagia.

Question 11

What are the consequences of damaging the marginal mandibular nerve?

Answer 11

Facial asymmetry and drooling.
Supplies orbicularis oris.

Question 12

When performing a submandibular gland excision - what are the important nerves and there anatomical relations

Answer 12

Marginal mandibular
- MMN emerges from Parotid Gland near angle of Mandible
- Mandibular branch runs downwards and forwards deep to Platysma
- Curves upwards to cross Mandible close to facial artery
- Mandibular nerve protected during surgery by making incision 3m below Mandible

Lingual Nerve:
* Deep to Mylohyoid
* Above the deep part of the Submandibular Gland
* Runs forward between Mylohyoid and Hyoglossus
* The lingual nerve then dips under the submandibular duct in a lateral to medial fashion, and runs forward on the surface of hyoglossus
* During ligation of Submandibular Duct, care must be taken to identify the lingual nerve so that it is not damaged
* More proximally, the Lingual Nerve is identified by retracting the Submandibular Gland laterally and the Mylohyoid muscle anteriorly
* Lingual Nerve is freed from the Submandibular Gland by dividing between the nerve and the Submandibular Ganglion

Hypoglossal Nerve:
* Lies deep and below the Submandibular Gland
* Runs between the Mylohyoid and Hyoglossus muscles
* Nerve identified after posterior border of the gland is mobilised and retracted upwards
* Mylohyoid also retracted anteriorly to expose the nerve as it emerges from the Posterior Belly of Digastric

Question 13

What are the clinical features of a carotid body tumour?

Answer 13

• Located anterior to the SCM, near the angle of the mandible, at the level of the hyoid bone.
  • The lump can move side-to-side but not up and down due to its location within the carotid sheath.
  • You can get dysfunction of the nerves which travel within the carotid sheath - this includes the glossopharyngeal, vagus, accessory and hypoglossal.
  • These tumours may synthesis and secrete catecholamines - although this is less common than phaeochromocytomas.

Question 14

What is the Shamblin criteria?

Answer 14

Use for carotid body tumours.

Class I - localised - splaying of bifurcation, little attachment to carotid.

Class II - partially surrounding carotids.

Class III - intimately surrounding carotids.

Question 15

What are the borders of the submandibular space?

Answer 15

Bordered by the mandible, mylohoid muscle, hyoid bone, and both belly’s of digastric.
The sublingual space is deep (superior) to this (on the deep surface of mylohyoid)
- Borders of sublingual space are mucosa of floor of the mouth, body of hyoid bone, mylohyoid muscle, medial aspect of mandible

The two spaces communicate with each other posteriorly (around the posterior border of mylohyoid).
Infection of these spaces results in Ludwigs angina which can cause airway obstruction.

Question 16

What are the boundaries of the pharyngeal space?

Answer 16

• Medial - pharyngeal wall
  
  • Lateral - medial pterygoid muscles.
  • Posterior - pre-vertebral fascia.
  • Anterior - pterygomandibular raphe.
  • Superior - base of the skull.
    
    • Inferior - level of the hyoid bone.

Question 17

What are the two compartments of the pharyngeal space - what are their contents and what separates them?

Answer 17

Divided into two compartments by the styloid process and its associated structures (stylopharyngeus muscle, styloglossus muscle, and stylohyoid ligament)

Pre-styloid compartment - contains fat and lymph nodes.

Retro-styloid compartment - contains the carotid sheath structures, cranial nerves, and sympathetic chain.

Question 18

What are the boundaries of the retropharyngeal space?

Answer 18

Bounded anteriorly by the buccopharyngeal fascia, which surrounds the pharynx muscles.
- Posteriorly is the pre-vertebral fascia.
- Is situated behind the hypopharynx and oesophagus
- Communicates with the parapharyngeal space laterally

The Alar fascia divides this space into two spaces, with the posterior space being termed the “danger space”
This danger space is continuous with the mediastinum.

Question 19

What are the boundaries of the oral cavity?

Answer 19

Wet lip mucosa.
Hard palate
Mylohyoid
Cicumvallate papillate of tongue.
Palatoglossus muscle (anterior tonsillar pillar)
Buccal mucosa of cheeks and retromolar trigone.

Question 20

How does upper aerodigestive cancer present?

Answer 20

Oral cavity
- Mouth pain or non-healing ulcers.
- Dysphagia
- Dysarthria (tongue cancer)
Nasopharynx
- Hearing loss or tinnitus
- Nasal obstruction
Oropharyngeal tumours
- Dysphagia
- Pain
- OSA or snoring.
Hypopharyngeal
- Dysphagia
- Odynophagia
- SOB
- Neck mass.
Larynx
- Hoarsness
- Dysphagia
- Chronic cough
- Haemoptysis.
- Stridor

Question 21

What is the the pathophysiology of salivary stone formation?

Answer 21

Salivary stasis
○ Reduced flow promotes precipitation of organic and inorganic materials.
○ Causes
§ Dehydration
§ Anticholinergic medications.
§ Poor oral intake.
§ Duct obstruction.
§ Gland inflammation.

Nidus formation.
○ Nidus forms from
§ Desquamated epithelial cells
§ Mucus
§ Bacterial debris.
§ Local injury
§ Inflammation

Mineral precipitation.
○ Saliva is supersaturated with
- Calcium and phosphate.

Question 22

Why are submandibular stones more common that parotid duct stones

Answer 22

Submandibular stones are draining against gravity, through a longer duct draining mucoid saliva with a high calcium saliva

Question 23

What is the non-operative management for sialolithiasis?

Answer 23

Conservative management
- Stay well hydrated
- Apply moist heat to area
- Massage the gland to milk the duct.
- Lemon drops - increase salivary flow
- NSAIDS
- Augmentin if secondary infection suspected

Question 24

What are the indications for endoscopic treatment of sialolithiaisis?

Answer 24

Sialoendoscopy - <4mm stone in parotid and <3mm stone in salivary - high chance of success.

Sialoendoscopy + laser lithotripsy - increases chance of success.

Question 25

What is a rannula and what is a plunging rannula?

Answer 25

Type of mucus cyst that occurs in the floor of the mouth. If forms due to obstruction or rupture of a salivary gland duct, typically involving the sublingual gland or, less commonly, the submandibular gland. This results in the accumulation of mucus in the surrounding tissues.

Question 26

What are the causes of acute salivary gland swelling?

Answer 26

Obstructive causes Strictures * Causes include radiation, trauma, prior infection, autoimmune process. * Treat with hydration, sialagogues (sour candy, Vitamin C), and massage. * Other options include steroid infusion, botox injection, ductal dilatation * Surgical options include sialoadenectomy or ductal reconstruction. Foreign body * Fish bone, grass blades, hair. Pneumoparotitis * Activities which increase intraoral pressure - CPAP, playing a wind instrument Inflammatory/Infection causes * Bacterial infection - often associated with anything that causes salivary stasis - dehydration, stones, strictures, anti-cholinergic agents, intubation. * Less common causes include mycobacterium and actinomycosis. Bilateral acute swelling * Radioactive iodine treatment (used for thyroid cancer) - develops in 50% of patients receiving RAI. * Iodine based contrast agents * Viral - HIV, EBV, CMV, HSV, HPV, Coxsackie, influenza * Mumps * Drug induced - clozapine

Question 27

What are the causes of chronic salivary gland swelling?

Answer 27

Chronic unilateral salivary swelling Neoplastic - see salivary gland tumour page Chronic bilateral salivary swelling Polycystic parotid disease - Rare condition resulting in cystic change, fibrosis, and epithelial proliferation within the gland. - Difficult to distinguish between this an a MEC. - Recommendation is complete excision Metabolic causes - Diabetes, metabolic syndrome, ETOH abuse, bulimia, malnutrition, and liver disease Immune mediated - Sjogren's disease ○ Lymphocytic infiltration of gland ○ 10% risk of developing non-Hodgkin lymphoma (MALT) within the gland - important to consider in a patient with known Sjogren's and new gland enlargement. ○ Rx - oral or intra-ductal steroids. - IgG4 disease ○ Diagnosis usually confirmed by biopsy - shows infiltration of IgG4-expressing plasmacytes. - Kussmaul disease ○ Allergic process by which the ducts get blocked with mucus. ○ Associated with elevated IgE levels and eosinophilia. ○ Rx with anti-histamines, oral or intraductal steroids Granulomatous - Sarcoidosis - ANCA-associated vasculitis. - Xanthogranulomatous sialadenitis. Other - HIV related. - Amyloidosis.

Question 28

What causes Frey syndrome?

Answer 28

Occur due to injury of the auriculotemporal nerve (V3) branches which carries both sensory fibers and parasympathetic secretomotor fibers to the parotid gland. - During the healing process, the severed parasympathetic fibers regenerate abnormally along the pathways of sympathetic fibers innervating the cutaneous sweat glands. - This means that when the patient thinks about food - instead of parotid secretion - cutaneous sweating occurs.

Question 29

What is the risk of malignancy for salivary gland tumours?

Answer 29

- 20% of parotid gland tumours are malignant. - 50% of submandibular gland tumours are malignant. - 80% of sublingual gland tumours are malignant. - 50% of minor gland tumours are malignant.

Question 30

What are the common benign tumours of the salivary glands?

Answer 30

- Most common type of benign tumour is a pleomorphic adenoma - 1/2 of all tumours. Other tumours include Warthin tumour, basal cell adenoma, and canalicular adenoma

Question 31

What are the most common malignant tumours of the salivary glands?

Answer 31

Most common malignant lesion is mucoepidermoid carcinoma and adenoid cystic carcinoma.

Question 32

What are the risk factors for salivary gland tumours?

Answer 32

- Radiation - Smoking - Warthin tumours are strongly associated with smoking. - Viral infections - HPV, EBV and HIV - Environmental factors - rubber manufacturing, hair dressers, beauty shops, nickel compounds.

Question 33

How do you workup a salivary. gland tumour?

Answer 33

Imaging - USS or MRI for local staging. - CT for distant staging. FNA - if non-diagnostic can repeat, core biopsy, or excise lesions FNA can be omitted if imaging is highly suspicious for malignancy - can go straight to an oncological procedure if appropriate

Question 34

What is the Milan criteria?

Answer 34

Question 35

What are the clinical features, histological features, imaging features of a pleomorphic adenoma?

Answer 35

- Presentation ○ Most common lesion - mainly in parotid. ○ Presents as painless mass. - Histology ○ Contain stromal material with epithelial and myoepithelial cells ○ Have a hyalinized stroma ○ Can have broad blunt extension (pseudopods) that project beyond the borders of the lesions but are not invasive - may contribute to recurrence. - Imaging - USS - usually appear as well defined, hypo-echoic and often lobulated masses

Question 36

Why is superficial parotidectomy recommended for a pleomorphic adenoma?

Answer 36

Superficial parotidectomy A carcinoma (usually salivary gland carcinoma) can arise from a pleomorphic adenoma thus they require parotidectomy- termed carcinoma ex pleomorphic adenoma. - 5% risk harbouring a carcinoma - High risk of local recurrence if a margin isn't taken of if capsule is ruptured. Radiation - Can be considered for positive margins (re-do surgery better), recurrence, inoperable primary tumour.

Question 37

What are the clinical, histological, and imaging features of a Warthins tumour? Whats the treatment?

Answer 37

Clinical ○ 2nd most common benign parotid tumour. ○ Strongly associate with smoking. ○ Frequently cystic and often bilateral. ○ Almost exclusively found in the parotid. Histology ○ Histology shows areas of cyst formation, a bilayered oncocytic epithelium, and lymphoid stroma. Imaging ○ On USS - appear as well defined, hypoechoic, smooth, cystic lesion. Treatment ○ If confident it is a Warthin tumour - can observe. ○ Often these lesions are growing OR there is diagnostic uncertainty - thus often superficial parotidectomy is performed.

Question 38

What are the clinical, imaging, and histology features of a MEC? Whats the treatment?

Answer 38

Clinical o Usually a low grade lesion o MEC is the most common malignant salivary gland tumour. o Usually found in the parotid gland. Histology o Mixture of mucin-producing columnar cells and squamous cells (called epidermoid cells) o Multiple grading systems used - best it Memorial Sloan Kettering which looks at presence of necrosis and >4 mitotic figures 10HPF. o Low grade lesions are cystic o High grade lesions are more solid Treatment o Superficial or Total parotidectomy o +/- neck dissection depending on involvement of nodes (drain to level II) o Neck dissection is sometimes done prophylactically if primary is a high risk lesion i.e. high grade, LVI, facial nerve involvement.

Question 39

What are the clinical, histological features of adenoid cystic carcinoma?

Answer 39

Clinical o Locally aggressive tumour with a high recurrence rate. o All cases are considered high grade lesions o Common in the minor glands (submandibular and sublingual) o Rarely has nodal metastasis but has a propensity for perineural spread. Histology o Three growth patters - tubular, cribriform or solid. o Cells shows scant cytoplasm, bland nuclei with no mitotic activity. Treatment o Treatment is with radical excision +/- neck dissection +/- RT.

Question 40

If performing a neck dissection for a salivary gland tumour - what stations should be dissected?

Answer 40

If the primary is being managed with surgery - should undergo a neck dissection - level II and III +/- levels I, IV, V as required. - Parotid - levels II/III (IV and V as required) - Submandibular - levels Ib, II and III IV and V as required)

Question 41

When would you perform a neck dissection for a patient with a salivary gland malignancies and no clinical nodes?

Answer 41

High risk tumour i.e. T3 or T4 High risk subtype i.e. adenoid cystic. Facial nerve involvement

Question 42

What is the role of radiotherapy in the management of salivary gland maligancies.

Answer 42

Can be given adjuvantly - PNI - LVI - high nodal burden - High risk tumour - positive margins. Can be given definitively - inoperable tumours - patients who are poor surgical candidates