11.1 Thyroid And Head And Neck Cancers

Question 1

What is often the first presenting sign of thyroid cancers and HNC?

Answer 1

Asymptomatic neck lump - cervical lymphadenopathy due to cervical lymph node Metastases

Question 2

What type of cancer are most HNC?

Answer 2

Squamous cell carcinomas

Question 3

Where do the largest proportion of HNC occur?

Answer 3

Oral cavity
Larynx
Oropharynx

Question 4

What are the main risk factors for HNC?

Answer 4

Heavy alcohol use
Tobacco
Increased age (60-70years)
Male Epstein-Barr virus infection (nasopharyngeal cancers)
Chewing of Betal nuts
Exposure to inhalants (hardwood)
Long term exposure to sun light or sun beds / radiation exposure
Family history
Human Papilloma Virus
Dental hygiene
Premalignant changes (leucoplakia/eryhtroplakia)

Question 5

How to HNC commonly clinically manifest?

Answer 5

Unexplained painful lesion
Mucosal ulceration or lesion within the oral cavity 
Unexplained hoarseness of voice
Dysphagia / Odynophagia 
Otalgia in an otherwise normal ear

Question 6

How are HNC usually staged and diagnosed?

Answer 6

Clinical examination
biopsy of the lesion (or neck lump)
imaging (e.g. CT/MRI)
Endoscopic investigation will be necessary for head and neck cancers involving the nasal cavity, pharynx and larynx

Question 7

Why is imaging of HNC necessary?

Answer 7

Evaluates the extent of the primary cancer, involvement of other structures and lymph nodes

Question 8

How is a neck lump biopsied?

Answer 8

Fine needle aspiration for cytology
Core biopsy
- always done under USS guidance

Question 9

Why is staging of the HNC important?

Answer 9

Determines appropriate treatment

Question 10

How are early stage HNC usually treated?

Answer 10

Surgery and radiotherapy

Question 11

How are more advanced HNC usually treated?

Answer 11

Surgery

Adjuvant chemotherapy

Question 12

Why is it important to have a multidisciplinary team supporting treatment of a patient with HNC?

Answer 12

Given the complexity of structures within the head and neck regions, treatments for most types of HNC will have some permanent and often significant implications on the anatomical structures essential for eating/drinking, speaking and breathing. Patients with HNC therefore require expert support from a variety of professional disciplines throughout their treatment.

Question 13

What health care professionals are commonly involved in the treatment of HNC?

Answer 13

radiologists
pathologists
specialist head and neck cancer surgeons
oncologists
dieticians 
speech and language therapists
Plastic surgeons

Question 14

What is the blood supply to the thyroid?

Answer 14

Superior thyroid artery - 1st branch of the external carotid artery
Inferior thyroid artery - arises from the thyrocervial trunk (a branch of the subclavian artery)

Question 15

Describe the venous drainage of the thyroid

Answer 15

Superior, middle and inferior thyroid veins. Form a venous plexus around the thyroid gland.
Superior and middle veins drain into respective internal jugular veins. Inferior drain into the brachiocephalic vein

Question 16

Why is the thyroid highly vascularises due?

Answer 16

As it is an important endocrine structure that secretes hormones directly into the circulation

Question 17

Who is the secretory function of the thyroid gland regulated?

Answer 17

By the pituitary gland

Question 18

How is the thyroid gland innervated?

Answer 18

Via the sympathetic trunk

Question 19

What anatomical structure is closely associated with the thyroid gland?

Answer 19

The recurrent laryngeal nerve - lies in close proximity to the thyroid. Care must be taken not to damage them during thyroid surgery

Question 20

Describe the pathway of the recurrent laryngeal nerve and how it relates to the thyroid gland

Answer 20

Branch from the vagus nerve within the chest and ascend up the neck to innervate the larynx.
Right RLN hooks under the right subclavian artery
Left RLN hooks under the arch of the aorta.
RLN then travels up the neck in a groove between the trachea and the oesophagus called the tracheoesophageal groove. Passes under the thyroid gland to innervate the larynx

Question 21

What is Leukoplakia?

Answer 21

Formation of thickened white patches on mucous membranes, particularly of the mouth and vulva

Question 22

What is erythroplakia?

Answer 22

An erythematous area on a mucous membrane

Question 23

What are risk factors for thyroid cancer specifically?

Answer 23

• Irradiation exposure (including radioactive iodine & radiation leaks)
• Family history and certain inherited conditions (e.g. FAP)

Question 24

What staging criteria is used for HNC?

Answer 24

TNM staging

Question 25

What determines the management of a patient with HNC?

Answer 25

1. Assessment - patients fitness for intervention, clinical staging, radiological staging 2. Biopsy 3. Discuss at multidisciplinary team meeting - curative or palliative intervention 4. Management with patient involvement

Question 26

How are cancers of the lip and oral cavity treated?

Answer 26

– Small tumours excise and repair the defect – Radiotherapy (bad morbidity) – Larger tumours that do not respond to RT may need extensive surgery (hemiglossectomy or total glossectomy)

Question 27

What are common resenting symptoms of a cancer of the larynx?

Answer 27

``` – Dyphonia (voice change)- main feature – Dyphagia – Referred otalgia – Globus – Neck lump – Weight loss – Cachexia ```

Question 28

What is a laryngetomy?

Answer 28

Surgical removal of the larynx, separating the airway from the mouth,nose and oesophagus. Done for large tumours of the larynx that do not respond to radiotherapy. Patient breathes through an opening in the neck known as a stoma

Question 29

Where is the thyroid gland?

Answer 29

Anterior neck, spans the C5 to T1 vertebrae. Lobes of thyroid are wrapped around the cricoid cartilage and superior rings of the trachea. Can be retrosternal

Question 30

What is the most common type of thyroid cancer?

Answer 30

Papillary adenocarcinoma

Question 31

What can cause recurrent laryngeal nerve palsy?

Answer 31

* Idiopathic * Laryngeal cancer * Thyroid disease (benign or malignant) * Trauma (including iatrogenic – ie. thyroidectomy) * Cervical lymphadenopathy * Oesophageal cancer * Apical lung cancer * Aortic aneurysm * Neuropathic (diabetes)

Question 32

What is the visceral compartment of the neck?

Answer 32

Compartment of the neck enclosed by the pre-tracheal fascia, with contributions from the buccopharyngeal fascia posteriorly. Contains the thyroid gland, trachea and oesophagus. Lies behind the muscular part of the pretracheal layer (contains the infrahyoid muscles).

Question 33

What are the 4 types of thyroid cancers?

Answer 33

Papillary adenocarcinoma Follicular adenocarcinoma Medullary carcinoma Anaplastic carcinoma

Question 34

How might a thyroid cancer present?

Answer 34

- enlarged thyroid gland or lump in the thyroid gland - usually thyroid function is unaffected (so TFTs would be normal- and will not report symptoms or signts relating to hyper or hypothyroidism.) Dysphagia Voice change

Question 35

How is thyroid cancer treated?

Answer 35

``` • Thyroidectomy (hemi or total dependant on type of Ca- most are total) • Radioactive Iodine • Radiothearphy/Chemotherapy ```