HNN Topic 15 - Arm, Pancoast Tumours Flashcards
Describe the staging of Pancoast tumours
Always T3/4
T3 = invade chest wall or sympathetic chain
T4 = invade spine, brachial plexus, blood vessels
Describe the location of the apex of the lung
Extends into root of neck, reaches above the level of the sternal end of the 1st rib
Where does the subclavian artery become the axillary artery?
From outer border of 1st rib
List the strap muscles of the neck
- Sternohyoid muscle
- Omohyoid muscle
- Sternothyroid muscle
- Thyrohyoid muscle
Describe the sympathetic innervation of the eye
- 1st order
- Posterolateral hypothalamus
- Brainstem to spinal cord, terminates at cillospinal centre (C8-T2)
- 2nd order (Preganglionic)
- Exit through T1 root, travel close to apex of lung (ventral ramus), paravertebral sympathetic chain stellate ganglion
- Terminate at superior cervical ganglion
- 3rd order (Postganglionic)
- Exit superior cervical ganglion into carotid canal to form plexus around internal carotid artery
- Plexus ascends into cavernous sinus, runs on CN VI then follows ophthalmic division of CN V to orbit
- Supplies iris dilatory muscles and smooth muscle fibres of upper and lower lid
- Vasomotor and sweat gland fibres follow external carotid artery to supply same side of face
Where is the stellate ganglion?
At level of C7 and neck of 1st rib
Which spinal nerves innervate the scalenus muscles?
C4-6
Define Pancost Tumour
- Malignany neoplasm of the superior sulcus of the lung
- Leads to lesions of the thoracic inlet and involvement of the brachial plexus and cervical sympathetic nerves
What is the clinical significance of the root of the neck?
The subclavian artery and vein and the brachial plexus pass between the thorax and upper limb by passing over the 1st rib and through the axillary inley - close association with the apex of the lung
Which spinal nerves contribute to the phrenic nerve?
C3, 4, 5 - mainly C4
Which areas are drained by the subclavian vein?
Upper limbs
List the branches of the brachial plexus
- Posterior cord - subscapular, thoracodorsal, axillary nerve, contines as radial nerve
- Lateral cord - musculocutaneous, lateral pectoral, median nerve
- Medial cord - medial pectoral nerve, medial cutaneous nerve of forearm + arm, ulnar nerve, median nerve
What is the action of the sternohyoid muscle?
Depresses hyoid bone
Describe the origin and insertion of the omohyoid bone
- Inferior belly - scapula to intermediate tendon
- Superior belly - intermediate tendon to hyoid bone
How are Pancoast tumours diagnosed?
X-Ray, CT, MRI, tissue biopsy
Describe the structure of the brachial plexus
- Roots - C5-T1
- Trunks - superior (C5/6), middle (C7), inferior (C8/T1)
- Divisons - anterior and posterior
- Cords -
- Lateral = anterior divisions of superior and middle trunks
- Posterior = posterior divisions of all 3 trunks
- Medial = continuation of anterior division of lower trunks
- Branches
- Lateral and medial cords join to form median nerve
- Posterior cord continues as radial nerve
- Lateral cord continues as musculocutaneous nerve
- Medial cord continues as ulnar nerve
Where does the radial nerve originate?
- Origin = C5/6, posterior cord
- Exits axilla under teres minor, runs around back of humerus in radial groove w/ arteria profunda brachii, passes down lateral forearm to wrist
Where does the mylohyoid muscle attach?
- Runs from mandible to hyoid bone, forms floor of oral cavity
- Medial fibres of two muscles join at midline raphe
Where is the superior sulcus of the lung?
Apical pleuro-pulmonary groove formed by the subclavian artery as it curves in front of the pleura
Which spinal nerves contribute to the great auricular nerve?
C2/3
What are the potential complications associated with Pancoast tumours?
- Horner’s sydrome
- Superior vena cava syndrome - facial swelling, cyanosis and dilation of veins of head/neck
- Arm oedema secondary to compression of blood vessels
Describe the origin of the internal jugular vein
- Formed by the union of the inferior petrosal and sigmoid sinuses at the jugular foramen
- Retromandibular, facial and lingual veins also drain into internal jugular vein
Describe the origin of the subclavian artery
- Receives blood from the aortic arch
- L directly from aorta
- R from brachiocephalic trunk
Which areas are supplied by the common carotid artery?
Head and neck
Why does arm oedema occur in Pancoast tumours?
- Subclavian vein compressed in axillary inlet - reduced drainage leads to blood pooling
- Reduced sympathetic function (compression of sympathetic ganglion) - reduced vessel tone, worse oedema
What is the function of the axillary nerve?
- Motor - deltoid and teres minor muscles
- Sensory - shoulder
- Cutaneous - shoulder/lateral arm
Define Horner’s syndrome
Condition characterised by miosis (constriction of pupil), ptosis (drooping of eyelid) and anhidrosis (absence of sweating on affected side of face)
Describe the path of the internal jugular vein
Originates at jugular foramen, runs down side of neck lateral to internal (then common) carotid artery, unites with subclavian vein at the root of the neck to form the brachiocephalic vein
List the spinal nerves which form the roots of the brachial plexus
C5, 6, 7, 8 and T1
Describe the dermatomes of the arm
What causes Horner’s syndrome?
- Interruption in function of sympathetic nerve fibres
- Many potential causes - trauma, tumour, stroke, birth trauma, demyelinating diseases, inflammation of lymph nodes of the neck
What is the function of the great auricular nerve?
Sensory innervation of skin over the parotid gland and mastoid process
Which areas are supplied by the subclavian artery?
Upper limb, head and thorax
Describe the diagnosis of Horner’s syndrome
- Ophthamologist - eye tests
- Neurological exam
- MRI, X-ray, CT
Describe the treatment of Horner’s syndrome
Dependent on cause, no specific treatment for Horner’s syndrome
Which areas are drained by the internal jugular vein?
Brain and superficial face/neck
Describe the origin and insertion of the sternocleidomastoid muscle
- Origin = manubrium and medial portion of clavicle
- Insertion = mastoid process of temporal bone, superior nuchal line
Describe the myotomes of the arm
- C5 = biceps (flexors of elbow)
- C6 = deltoids, extensor carpii (extension of wrist)
- C7 = triceps (extension of elbow)
- C8 = palmar interossei (finger flexion)
- T1 = dorsal interossei (finger abduction)
What is the action of the thyrohyoid muscle?
Elevates thyroid, depresses hyoid
Where does the ulnar nerve originate?
- Origin = C7-T1, medial cord
- Descends medial side of arm in front of medial head of triceps to elbow, enters flexor compartment of forearm + travels to wrist
List the symptoms of a Pancoast tumour
- Not typical lung cancer symptoms e.g. cough, shortness of breath
- General symptoms of cancer - weight loss, fatigue
- Pain in shoulder, arm or axilla
- Weakness or wasting of the arm/hand
- Pain, numbness, tingling in arm/hand
- Horner’s syndrome
- Hoarse voice/bovine cough - compression of recurrent laryngeal nerve
Describe the anatomical position of scalenus medius
Posterior to the brachial plexus and subclavian artery
What is the function of the radial nerve?
- Motor - extensors of elbow, wrist, hand
- Sensory - elbow, wrist, hand
- Cutaneous - skin over posterior upper limb
What is the action of the sternocleidomastoid muscle?
Cervical rotation and flexion, elevation of sternum - involved in forced inhalation
What is the function of the transverse cervical nerve?
Cutaneous innervation of antero-lateral parts of the neck
What is the first branch of the external carotid artery? Where does it arise?
Superior thyroid artery is 1st branch of external carotid artery, arises just below hyoid bone
Which areas are supplied by the external carotid artery?
Face, scalp, skull and meninges
Where does the axillary nerve originate?
- Origin = C5/6, posterior cord
- Descends behind axillary artery, winds around surgical head of humerus
What are the terminal branches of the external carotid artery?
Maxillary and superficial temporal arteries, divides in parotid gland
Where does the external carotid artery originate?
From the common carotid artery at the level of the thyroid cartilage (C4)
List the risk factors for Pancoast tumours
- Smoking, exposure to other carcinogens e.g. asbestos
- Other cancers esp. breast, thyroid
- Bacterial/fungal infections
Describe the attachments and action of the sternothyroid muscle
- Manubrium to thyroid cartilage
- Depresses thyroid cartilage
What is the function of the musculocutaneous nerve?
- Motor - flexors of elbow
- Cutaneous - skin over lateral forearm
What is the function of the phrenic nerve?
Motor and sensory innervation of the diaphragm
Describe the sensory innervation of the hand
What is the function of the ulnar nerve?
- Motor - flexors of forearm, medial muscles of hand
- Sensory - medial aspect of hand
- Cutaneous - skin of medial hand
What forms the stellate ganglion?
Inferior cervical ganglion and 1st thoracic ganglion
Which areas are supplied by the interal carotid artery?
Brain
Where does the median nerve originate?
- Origin = C5-T1, medial and lateral cords
- Leaves axilla with brachial artery, travels to elbow then wrist, enters carpal tunnel, divides into medial and lateral branches
What is the action of the omohyoid muscle?
Depresses larynx and hyoid bone
Describe the path of the common carotid artery
- R from brachiocephalic trunk, L from aortic arch
- Divides in neck to form internal and external carotid arteries at upper border of thyroid cartilage (C4)
Which nerve innervates the digastric muscle?
Mandibular division of trigeminal nerve
Where does the musculocutaneous nerve originate?
- Origin = C5-7, lateral cord
- Descends between biceps + brachialis to elbow, becomes continuous with lateral cutaneous nerve of forearm
Describe the treatment of Pancoast tumours
- Depends on patients health, size and location of tumour
- Aim - reduce symptoms, remove cancer
- Main treatments
- Chemotherapy
- Radiation therapy
- Surgery
- Symptom relief - analgesics, steroids - reduce nerve pressure
What is the function of the median nerve?
- Motor - flexor + pronator muscles in anterior compartment of forearm, thenar muscles and lateral lumbricals in hand
- Sensory - lateral hand
- Cutaneous - skin of elbow, wrist and radial aspect of hand
List the branches of the subclavian artery
- Vertebral artery
- Internal thoracic artery
- Thyrocervical trunk
- Costocervical trunk
- Dorsal scapular artery
- Continues as axillary artery
Describe the origin and insertion of the sternohyoid muscle
- Origin - manubrium of sternum
- Insertion - hyoid bone
Which spinal nerves innervate the omohyoid muscle?
C1-3
Which nerve innervates the thyrohyoid muscle?
Hypoglossal nerve - C1
Which spinal nerve contribute to the transverse cervical nerve?
C2/3
Describe the origin and insertion of the thyrohyoid muscle
- Origin - thyroid cartilage
- Insertion - hyoid bone
Describe the origins and path of the subclavian vein
- Continuation of axillary vein, joins internal jugular vein to form the brachiocephalic vein
- Angle of union of subclavian vein and internal jugular vein = venous angle
- Follows subclavian artery, separated by the anterior scalene muscle
Describe the structure of the digastric muscle
- Two bellies - anterior and posterior
- Anterior belly origin = digastric fossa of mandible
- Posterior belly origin = mastoid notch of temporal bone
- Insertion - intermediate tendon of hyoid bone
List the complications of a stellate ganglion block
- Horner’s syndrome
- Swallowing problems
- Vocal cord paralysis
