20 - Head and Neck Cancers Flashcards
What is the blood supply to the thyroid gland?
- Superior artery from ECA
- Inferior artery from thyrocervical trunk
- There is a superior, middle and inferior vein that drain back to internal jugular and brachiocephalic (inferior). Form a venous plexus
What is the course of the recurrent laryngeal nerve?
- From the vagus nerve goes down and back up into tracheooesophageal groove
- Left on arch of aorta and right on subclavian artery
What is the relationship between the superior laryngeal nerve and the thyroid?
Internal branch pierces the thyroid whilst the external supplies the larynx
What surrounds the trachea?
- Pretracheal fascia
- Infrahyoids lie anteriorly to it
What is the main type of cancer that occurs in the head and neck?
- Squamous Cell Carcinoma (apart from thyroid cancers)
- Most common in oral cavity, larynx and oropharynx
What are the risk factors for head and neck cancers?
- Male, older age (60-70), smoking, alcohol, betal nut chewing
- Occupation e.g exposure to hardwood
- Pre-malignant changes e.g. white patches (leucoplakia) or red patches (erythroplakia) seen on tongue
- HPV virus in oropharyngeal cancers
- EBV in nasopharyngeal
- Exposure to sunlight in lip cancers
- Thyroid cancer are previous radiation exposure/ family history
What is happening to the incidence of head and neck cancers and why?
Rising, particulary in 30-40 year old due to HPV, even though smoking has decreased
What is the most common presentation of a head and neck cancer and some other symptoms a patient might present with?
Asymptomatic neck lump (cervical lymphadenopathy)
Also:
- Hoarseness of voice
- Dysphagia
- Odynophagia
- Otalgia with normal ear (pharynx and larynx)
- Mucosal ulceration e.g erythroplakia
How are head and neck cancers diagnosed?
- Clinical examination and biopsy under ultrasound guidance
- CT/MRI
- Endoscopy for larynx biopsy
How do we stage head and neck cancers?
T: size of tumour and location
N: degree of lymph node involvement
M: presence of distant metastases
Distant metastases (particularly in lung) have poor prognosis and often incurable. Need to stage to choose appropriate treatment
How are head and neck cancers often treated?
- Early stage by surgery or radiotherapy. Lasers or radical neck dissection
- Late stage surgery and adjuvant chemotherapy
- Incurable late stage then palliative
- Need MDT approach as lots of functions, e.g swallowing and talking, lost when surgery
What is a radical neck dissection?
Removal of tumour, all ipsilateral lymph nodes, spinal accessory nerve, IJV and SCM
What are some different specialities that may be on an MDT team to plan for a radical neck dissection?
- Radiologist
- Pathologist
- Oncologist
- Dietician
- Plastic surgeon
- S and L therapist
- Head and neck surgeon
What are palliative care plans for a patient with an incurable laryngeal cancer?
Support with feeding, swallowing, pain, voice rehab
How does an oral cavity (lips and tongue) cancer often present and how do we investigate this further?
- Usually SCC
- Unexplained lump or non-healing lesion e.g leukoplakia
- Side of tongue and lip
- Pain or problems swallowing
- Risk factors: alcohol, HPV, long term sunlight (lip)
How does a pharyngeal cancer often present and how do we investigate this further?
- Lump in neck
- Hearing loss or otalgia
- Change in voice
- Weight loss
- Bad breath
- Difficulty or pain swallowing
- Risks: hardwood, EBV, HPV, drinking, smoking, betel nut, high salt diet
How does a laryngeal cancer often present and how do we investigate this further?
- Dysphonia
- Dysphagia
- Otalgia
- Neck lump
- Cough
If advanced need to do laryngectomy to breathe out of neck. If small surgery and radio
What is the difference between a tracheostomy and a laryngectomy?
Larynx is completely removed in laryngectomy so trachea on anterior neck
How does thyroid cancer often present?
- Neck lump (goitre or lymphadenopathy)
- Compressive symptoms, e.g dysphagia
- Voice change
- Thyroid function often unaffected
How do we investigate a suspected thyroid cancer?
Triple assessment
Clinca full history and examination
- Imaging by ultrasound as superficial
- Biopsy under ultrasound by aspiration for cytology
What is the most common malignancy in the H and N and the thyroid?
- H and N: SCC
- Thyroid: see image PFAM
If cancer of the thyroid is confirmed by biopsy what is the next step?
- Thyroidectomy followed by radioactive iodine and radio/chemo
- Can damage superior and recurrent laryngeal nerve
What are some differential diagnoses for a recurrent laryngeal nerve palsy?
What are some structures that run through the posterior triangle of the neck?
- Inferior belly of omohyoid
- Subclavian vein in front of anterior scalene, artery behind
- Scalenes form the floor
What are some important nerves that are related to the scalene muscles?
- Phrenic nerve runs on anterior surface of anterior scalene
- Brachial plexus passes between anterior and middle scalenes
What is a thyroid ima and why can it cause issues?
- Unpaired artery from brachiocephalic trunk that supplies the thyroid gland that happens in 10% of people
- Supplies the isthmus and anterior surface
What is the likely diagnosis of this patients neck lump?
Thyroglossal cyst
What nerves contribute to the cervical plexus and where is it located?
- Anterior rami of C1 to C4
- Line on scalenus medius and levator scapulae deep to SCM
- Sensory branches emerge from posterior border of SCM
- Found in posterior triangle
Where do the sensory branches of the cervical plexus supply?
- Skin of neck
- Part of scalp and ear
- Superior thorax (C2 to C4)
Yellow nerves on image
What is the ansa cervicalis?
- Motor branch loop from the cervical plexus that supplies the infrahyoids. C1 to C3
- Acts to depress the hyoid
- Sits on top of IJV
What other motor branch comes from the cervical plexus apart from the ansa cervicalis?
- Phrenic nerve C3, C4, C5
What is a cervical plexus block?
- When doing any neck surgery, e.g lymph node dissection or thyroidectomy, can anaesthatise the nerves
- Nerve point: midway posterior SCM
- This is the point where all of the sensory nerves enter the skin
