Session 2 Flashcards
What is lymphadenopathy?
- Enlargement of lymph nodes
- Can involve one or several lymph nodes
- Usually identified as a neck lump
Why does lymphadenopathy occur?
- Due to infection and/or inflammation in the tissues drained by that lymph node.
- Due to malignancy - either metastases or primary malignancy (lymphoma)
- Most common cause is swollen lymph node secondary to recent infection.
What else can cause a neck lump (other than lymphadenopathy)?
- Pathology of the thyroid gland
- Congenital conditions
How can we determine the likely cause of lymphadenopathy?
- Location of lump
- Palpation findings
- Any red flags found e.g. certain associated symptoms and lymph nodes with particular characteristics to palpation.
Why is knowledge of the lymphatic drainage of the head and the neck region important?
- The presence of an enlarged lymph node may signal disease in the area it drains.
How are the lymph nodes of the neck organised?
- There are regional (superficial) and terminal (deep) groups.
Which groups of lymph nodes are regional?
- Occipital nodes
- Post auricular (also called retroauricular or mastoid) nodes.
- Submandibular nodes
- Regional lymph nodes drain specific areas
Where do regional lymph nodes lie?
- Superficially within the superficial cervical fascia
- This means they can be readily palpated when they are enlarged.
Where do terminal lymph nodes lie?
- Within the neck deep to the investing layer of deep cervical fascia.
Where do terminal lymph nodes receive their lymph from?
- They receive all the lymph from the head and neck, including lymph drained first via the regional groups.
- Deep tissues and structures of the neck e.g. larynx and thyroid gland drain directly to deep cervical lymph nodes.
Pathology of which structures may first present with a lump in the neck?
- Larynx, thyroid gland
- Because these structures drain directly to the deep lymph nodes.
Which structure are the deep cervical lymph nodes closely related to?
- Internal jugular vein within the carotid sheath
Give 2 examples of terminal cervical node
- Jugulodigastric node (tonsillar node)
- Jugulo-omohyoid node
Where is the jugulodigastric node located?
- Just below and behind the angle of the mandible.
Which structures drain to the jugulodigastric node?
- Palatine tonsil
- Oral cavity
- Tongue
- Often swollen and tender in tonsillitis and can become enlarged in cancers affecting these structures.
Which structures drain to the jugulo-omohyoid node?
- Tongue
- Oral cavity
- Trachea
- Oesophagus
- Thyroid gland
What are the supraclavicular nodes?
- A group of deep cervical nodes found in the posterior triangle, at the root of the neck on either side.
- Can enlarge in the late stages of malignancies of the abdomen and thorax.
- Receive lymph from the abdomen and thorax before drainage via thoracic duct into venous circulation.
From where does the arterial supply to the head and neck arise?
- Right and left common carotid arteries
- Vertebral arteries (branches of the subclavian arteries)
Which parts of the body are supplied by the vertebral arteries?
- Posterior neck
- Posterior parts of the brain e.g. brainstem, cerebellum
Describe the path taken by the vertebral artery
- Ascends through transverse foramina of the cervical vertebrae (except C7)
- Enters subarachnoid space between atlas and occipital bone.
- Passes up through foramen magnum
- Both vertebral arteries join to form basilar artery
Where do the common carotid arteries originate from?
- Right originates from brachiocephalic artery
- Left originates directly from arch of aorta
- Therefore left CCA is longer - it courses for about 2cm in the superior mediastinum before entering the neck.
What is the carotid sheath?
- A fascial envelope containing the CCA, IJV, and vagus nerve.
- Runs deep to sternocleidomastoid muscle
- Sheath is thin over vein but thicker around artery.
How are the contents of the carotid sheath arranged?
- Artery lies medially
- Vein is lateral
- Nerve lies behind and in between the vessels
- Sympathetic chain lies outside the sheath, medially and
How are the contents of the carotid sheath arranged?
- Artery lies medially
- Vein is lateral
- Nerve lies behind and in between the vessels
- Sympathetic chain lies outside the sheath, medially and behind it.
What happens once the common carotids have terminated?
- Termination occurs at C4 level - the upper border of the thyroid cartilage.
- They divide into internal and external carotid arteries.
- At this division, internal carotid artery is more bulbous due to carotid sinus.
Why is the site of the carotid sinus clinically important?
- Rubbing this area firmly can alleviate supra-ventricular tachycardias.
How is the internal carotid artery distinguished?
- By a lack of branches in the neck
Outline the path taken by the internal carotid artery
- Ascends, then enters the base of the skull through the carotid canal.
- Courses intracranially through the cavernous sinus
- Upon exit of the cavernous sinus, internal carotid artery gives its branches, which supply the brain and the eye.
What are the names of the branches given by the external carotid artery?
- Superior thyroid artery
- Ascending pharyngeal artery
- Lingual artery
- Facial artery
- Occipital artery
- Posterior auricular artery
- Maxillary artery
- Superficial temporal artery
Which are the terminal branches of the external carotid artery?
- Maxillary branch - supplies deep tissue and bone structures of the face.
- Superficial temporal artery - supplies tissues of the scalp.
- Both arteries arise and travel within the parotid gland, so supply it with blood.
What is a key branch of the maxillary branch of the external carotid artery?
- Middle meningeal artery
- Supplies the meninges and skull bones.
What is temporal arteritis?
- Vasculitis of the superficial temporal artery
- Presents in older people as a unilateral headache and jaw claudication.
- Serious and requires urgent treatment.
Outline the path taken by the facial vein
- Runs from the medial angle of the eye to the inferior border of the mandible.
- Then joins with IJV
- Also connects with both superior and inferior ophthalmic veins
Which structures do the ophthalmic veins directly connect to?
- cavernous sinus
- pterygoid venous plexus
What are the clinical implications of the cavernous sinus?
- It allows blood draining via the facial vein to drain intracranially.
- This means that infections involving the face can spread to involve intracranial structures.
What is a cavernous sinus thrombosis?
- Septic thrombi in the facial vein travel via the ophthalmic veins to the cavernous sinus.
- Very serious
- Very rare
What structure provides a potential route for infection of the scalp to spread into the cranial cavity?
- The anastomosis between the extra-cranial veins and intra-cranial venous sinuses.
- Emissary veins run through the skull connect these vessels and provide a route for infection to spread.
Outline the course of the IJV
- Arises as a continuation of the sigmoid sinus, a venous structure found within the skull.
- Runs the length of the neck in a straight line from the lobule of the ear to the sternoclavicular joint.
- Ends by joining with subclavian vein to form brachiocephalic vein.
- This then drains into the superior vena cava and then to the right atrium.
What enables us to insert central lines into the IJV?
- Through most of its course, the sternocleidomastoid muscle covers the IJV.
- Towards the inferior end of the vein, the muscle splits into its clavicular and sternal heads.
- This creates a gap anterior to the vein.
- JVP can also be seen here
Why do doctors measure JVP?
- To give an indication of the pressures within the venous circulation of the heart.
- Right JVP is favoured over left.
Which veins drain into the IJV?
- Facial vein
- Veins draining the thyroid gland and the tongue.
What forms the EJV?
- Veins that have drained the scalp and the deep structures of the face join together.
Outline the passage taken by the EJV
- Runs just beneath the skin in the superficial fascia of the neck.
- Deep to platysma but superficial to sternocleidomastoid.
- Drains into subclavian vein
Why are the vessels of the neck important?
- Major vessels supplying and draining the brain
- Access route
- Important in clinical examination
- Pathology can be seen in disease or injury to these vessels
What is the brachiocephalic trunk?
- 1st branch of aorta
- Gives rise to right subclavian vein and common carotid artery
What key branches arise from the subclavian artery?
- Vertebral artery
- Thyrocervical artery - inferior thyroid artery branches off from here and runs close to recurrent laryngeal nerve
At what level does the common carotid artery bifurcate?
- Superior border of thyroid cartilage
- Level of C4
What is the superior border of the carotid triangle?
- Posterior belly of digastric muscle
What is the medial/inferior border of the carotid triangle?
- Superior belly of omohyoid muscle
What is the lateral border of the carotid triangle?
- Medial border of sternocleidomastoid
Why is the carotid triangle important?
- Bifurcation of common carotid artery occurs within triangle
- Important clinically for access of carotids, IJV, vagus nerve, hypoglossal nerve, central line placement
- Carotid arteries susceptible to atherosclerosis at bifurcation
- Carotid sinus massage
- Central pulse
Why is atherosclerosis serious in carotid arteries?
- Occurs commonly at bifurcation
- Causes artery to stenose
- Plaque rupture can release an embolus
- Embolus can travel to brain and cause stroke or TIA
- Can also cause transient loss of vision if clot enters artery supplying eye
What is a carotid endarterectomy?
- Incision into the neck and wall of carotid artery
- Removal of plaqyue tissue
- Incision stcihed back up to repair artery
What is a carotid sinus massage?
- Pressure at side of carotid bodies
- Increased baroreceptor activity feedback slows heart down
- Treats tachycardia
What makes the IJV ideal for central venous lines?
- Large central vein
- Superficial
- Easily accessible
Where is the carotid canal found?
- Within petrous part of temporal bone
Where is the cavernous sinus found?
- Upper surface of sphenooid bone
What structures run through the cavernous sinus?
Carotid artery
- Oculomotor nerve (cranial nerve III)
- Trochlear nerve (cranial nerve IV)
- Abducens nerve (cranial nerve VI)
- 2 branches of cranial nerve V (trigeminal, ophthalmic, maxillary)
Outline the route of the ophthalmic artery
- Follows alongside optic nerve
- Gives of branch called central retinal artery
What are the branches of the internal carotid artery?
- Ophthalmic artery
- Anterior cerebral artery
- Middle cerebral artery
- Posterior communicating artery
- These branches provide arterial blood to the brain and form the anterior circulation of the circle of Willis
What are the symptoms of giant cell arteritis/temporal arteritis?
- Frequent, severe headaches
- Scalp tenderness, particularly over the temple
- Jaw pain while eating/talking
- Loss of vision/visual changes
- Must be treated quickly with high dose steroids otherwise patients can permanently lose their eyesight
Which vessels supply the scalp with blood?
- From internal carotid artery: supraorbital artery and supratrochlear artery
- From external carotid artery: superficial temporal artery, posterior auricular artery, occipital artery
Why does the scalp bleed so heavily?
- Artery walls held open by connective tissue so can’t constrict
- Lots of anastomoses
- Lacerations deep enough to involve epicranial aponeurosis of occipitofrontalis can pull cuts open
Describe the pathway taken by the middle meningeal artery
- Enters skull via foramen spinosum
- splits into anterior and posterior middle meningeal artery
- anterior branch passes under Pterion of skull
- travels on external surface of periosteal dura mater
How does rupture of the middle meningeal artery occur?
- The pterion (under which middle meningeal artery passes) is a thin area of bone
- fracture at site of pterion can rupture the MMA
- causes an extradural haemorrhage
How is an extradural haemorrhage treated?
- Needs specialist neurosurgical treatment
- Craniotomy - open cranium to relieve pressure
- Evacuate blood clot forming and stop the bleeding
What is the danger triangle of the face?
- The region where the facial vein can drain backwards into the cavernous sinus
- Infections in that area can spread via the facial vein and end up in the dural venous sinuses
What are the dural venous sinuses?
- Superior sagittal sinus
- Inferior sagittal sinus
- Cavernous sinus
- Sigmoid sinus
- Transverse sinus
How do you measure JVP?
- Look at right internal vein
- Patient at 45 degrees
- Head turned slightly to left
- Look for pulsations through sternocleidomastoid
- Measure height from sternal angle and add 5cm
What is the role of the lymphatic system within the body?
- Remove excess fluid from interstitial space
- Return smalls proteins and fluid that leaked from capillaries
- Key role in immune defence and surveillance
What do lymph nodes act as?
- Physical filters
- Phagocytic filters
- Full of lymphocytes (T and B cells) that activate and proliferate in response to antigens
- This causes lymph nodes to enlarge
What is Waldeyer’s ring?
- An annular collection of lymphoid tissue arranged around the opening of the nose and mouth in a ring of defence
- Found just beneath mucosa
- Contains pharyngeal tonsil, tubal tonsil, palatine tonsil, lingual tonsil
What is the significance of the pharyngeal tonsil?
- Sits in nasal pharynx
- Enlargement of this tonsil can lead to obstruction of nasal breathing and blockage of Eustachian tube
- This results in middle ear problems
What is a lymph node?
- A collection of lymph vessels surrounded by a tough exterior capsule
What do lymph nodes that have enlarged due to infection feel like?
- Tender
- Mobile i.e. does not feel stuck to surrounding tissues
- Likely recent rapid enlargement
What do lymph nodes that have enlarged due to malignancy feel like?
- Hard, tethered to surroundings and painless to palpation = suggestive of metastases
- Rubbery, painless to palpation and fast-growing = cancer of lymph node itself e.g. lymphoma
What are the red flags for lymphadenopathy?
- Persisting > 6 weeks
- Fixed, hard, irregular on palpation
- Rapidly growing in size
- Size >2cm
- Associated with generalised lymphadenopathy
- Associated systemic signs and symptoms
- Associated with a persistent unexplained change in voice/hoarseness/difficulty swallowing
Which superficial lymph nodes drain the face, scalp and the skin of the neck?
- Sub-mental
- Sub-mandibular
- Pre-auricular and parotid
- Post-auricular
- Occipital
- Superficial cervical associated with EJV
- Posterior cervical associated with EJV
- Anterior cervical associated with AJV
What is drained by the post-auricular nodes?
- Posterolateral half of scalp
What is drained by the pre-auricular and parotid nodes?
- Anterolateral scalp
- Upper half of face including eyelids
- Cheks
What is drained by the submental nodes?
- Inferior and posterior chin
- Floor of mouth
- Tip of tongue
- Lower incisor teeth and gums
What is drained by the submandibular nodes?
- Centre of face and cheeks
- Teeth and gingivae
- Parts of anterior tongue
What is drained by the occipital nodes?
- Posterior scalp
What is drained by the supraclavilcular nodes?
- Parts of thoracic and abdominal cavity
- Left nodes drain abdominal cavity and thorax - called Virchow’s node
- If left nodes enlarged, indicates gastric cancer
- Right nodes drain mid-section of chest, oesophagus and lungs
How would you take the history of a patient with a neck lump?
- Age
- How long present?
- How has the lump changed over time?
- Associated symptoms/signs
- Potential risk factors
How would you examine a neck lump?
- Identify if its location is midline or lateral
- If lateral, is it in the anterior or posterior triangle?
- Is there any movement with swallowing (indicates relationship to thyroid gland)
- Is there any movement with sticking out tongue (indicates thyroglossal duct cyst)
- Palpate lump and note its features
What questions should you consider when palpating a neck lump?
- Does it feel superficial or deeper?
- Is it mobile or fixed to surrounding tissue?
- Hard or soft?
- Smooth or irregular?
- Does it feel fluctuant, as if filled with fluid?
- Tender?
- Any overlying skin changes?
What are the possible causes of a neck lump?
- Benign lesions of skin or subcutaneous tissue
- Cervical lymphadenopathy, benign or malignant
- Congenital lesions
- Thyroid gland pathology
- Salivary gland pathology
- Vascular
Give examples of benign lesions of skin or subcutaneous tissue that could cause a neck lump
- Sebaceous cyst
- Lipoma
Give examples of congenital lesions that could cause a neck lump
- Thyroglossal duct cysts
- Branchial cysts
- Dermoid cysts
- Laryngocoele
- Cystic hygromas
Give examples of thyroid gland pathology that could cause a neck lump
- Malignant or benign neoplasms
- Grave’s disease
Give examples of salivary gland pathology that could cause a neck lump
- Calculus
- Inflammation or infection
- Neoplasm, benign or malignant
Give examples of vascular conditions that could cause a neck lump
- Carotid body tumour
- Aneurysm
What is the first-line imaging choice for investigating a neck lump?
- Ultrasound
