Thyroid and Head and Neck Cancer Flashcards
Does the internal carotid artery given any branches in the neck?
No!
Describe the blood supply to the thyroid
Arterial supply:
- superior thyroid artery- a branch of the external carotid. Supplies superior and anterior portions of the gland
- inferior thyroid artery- a branch of thyrocervical trunk. Supplies the inferior and posterior portions of the gland
Venous drainage:
- superior and middle veins drain to the internal jugular vein
- inferior thryroid vein drains to brachiocephalic vein
Where is the thryoid located?
The anterior neck between C5-T1 vertebrae
Enclosed within pre-tracheal fascia and the infrahyoids lie anterior to it
Describe the route of the recurrent laryngeal nerve
Right:
- Branch of the right vagus nerve hooks around the right subclavian artery and back to the larynx
Left:
- Branch of the left vagus nerve hooks around the arch of the aorta and back to the larynx
- Longer route so more vulnerable to damage
What is the main type of cancer of the head and neck?
Squamous cell carcinoma excluding thyroid cancers
Give some tumour sub sites of the head and neck
- Lip/ oral cavity
- Pharynx
- Larynx
- Nasal cavity / sinuses
- Salivary glands
- Thyroid
Give some of the risk factors of Head and Neck cancers
- Male
- Smoking
- Older age
- Alcohol
- Betal nut chewing
- HPV virus for oropharyngeal cancers
- EBV for nasopharynx cancers
- Sunlight exposure
What are the different subtypes of larygneal cancer?
- Supraglottis
- Glottis
- Subglottis
What are some risk factors for specifically developing thyroid cancer?
- Irradiation exposure (radioactive iodine and radiation leaks)
- Family history of certain hereditary conditions e.g. FAP
What is the staging system used for head and neck cancers?
TNM
Tumour (size)
Nodes (involvements of lymph nodes)
Metastasis (spread to distant sites)
How would you investigate HNC further?
- Biopsy (easy if on the lip)
- Endoscope to visualise larynx /pharynx and take biopsy
- Clinical staging
- Radiological staging
How might a lip/oral cavity cancer present?
- lump
- pain (including referred pain to the ear)
- fixation of the tongue
- dysphagia
- pain on swallowing (odynophagia)
How might pharyngeal cancer present?
- lump
- pain (incliuding referred ear pain)
- dysphagia
- odyniphagia
- weight loss
- often presents late so 25% are untreatable at presentation
How might laryngeal cancer present?
- dysphonia (change in voice) main feature
- dysphagia
- referred otaliga
- neck lump
- weight loss
- cacexia (wasting of the body)
What is the difference between larygectomy and tracheostomy?
Larygectomy = whole voice box is removed, left with a whole to allow air flow
Tracheostomy = anatomy kept the same but there is a hole in the trachea
