Pancoast Tumour

Question 1

What is a Pancoast tumour?

Answer 1

A malignant neoplasm of the superior sulcus of the lung.

Question 2

What type of cancer is a pancoast tumour usually?

Answer 2

SCC

or Small cell carcinoma.

Question 3

What structures are at risk of impingement from a pancoast tumour?

Answer 3

Stellate ganglion and cervical sympathetic nerves.
Brachial plexus.
Subclavian vein.
Recurrant laryngeal nerve.

Question 4

What occurs due to compression of the subclavian vein?

Answer 4

Failure of venous return causing oedema, tenderness, warmth and erythema.
(Loss of vascular tone also occurs due to loss of sympathetic innervation).

Question 5

Which nerve roots of the brachial plexus are at risk from invasion by a pancoast tumour? How would these result in symptoms?

Answer 5

C8: Pain and weakness in the medial forearm, pinky and ring ringer. Can lead to atrophy of the interosseous muscles.
T1: Pain in medial forearm.

Question 6

What happens if the recurrent laryngeal nerve is compressed by a tomour?

Answer 6

Hoarse cough.

Question 7

What happens when the stellate ganglion is compressed by a tumour?

Answer 7

Horners syndrome - miosis, ptosis and anhydrosis.

Question 8

How is a pancoast tumour diagnosed?

Answer 8

Imaging: CT, MRI, PET

Biopsy.

Question 9

How is a pancaost tumour managed?

Answer 9

Pre-surgical staging using imaging and biopsy.
Due to relationship with other structures in the thoracic inlet, neo-adjuvant radiotheraphy can be used to downsize the tumour (30 Gy for 2 weeks).
Resection of the chest wall, lower brachial plexus and en bloc lung resection. 5 year survival rate = 30%.

Question 10

Why would a patient with a pancoast tumour not receive surgery?

Answer 10

If the tumour invades past T1.

Question 11

Where is the thoracic inlet?

Answer 11

Between the clavicle and rib 1.

Question 12

What main structures pass through the thoracic inlet?

Answer 12

Trachea, oesophagus, thoracic duct.
Apex’s of lungs.
Phrenic, vagus, recurrent laryngeal, sympathetic trunks.
Left and right common carotid arteries.
Left subclavian artery.
Internal jugular, brachiocephalic and subclavian veins.
Lymphatics.

Question 13

Describe the sympathetic pathway to the eye.

Answer 13

1. Arise from the hypothalamus and descend through the brainstem to terminate in the ciliospinal centre (C8-T2).
2. Pre-ganglionic fibres exit through the T1 root and travel close to the lung apex through the sympathetic chain and stellate ganglion. They terminate at the superior cervical ganglion.
3. Post-ganglionic fibres exit the superior cervical ganglion and form a plexus surrounding the carotid artery. This plexus ascends to the cavernous sinus and runs along CN VI and then follows CN V to reach the orbit. It supplies the pupil dilator muscles and smooth muscle fibres of the upper and lower eyelids.

Question 14

What are the characteristics of Horners syndrome?

Answer 14

Miosis: Pupil constriction
Ptosis: Droopy eyelid
Anhydrosis: Decreased sweating.

May also get redness of the cheek and ear, and enophthalmos (the appearance of posterior displacement of the eye).

Question 15

What are the roots of the brachial plexus?

Answer 15

C5, 6, 7, 8, T1.

Question 16

What are the trunks of the brachial plexus?

Answer 16

Superior, middle, inferior.

Question 17

What are the cords of the brachial plexus?

Answer 17

Lateral, posterior, medial.

Question 18

What are the branches of the brachial plexus?

Answer 18

Musculocutaneous
Axillary 
Median 
Radial 
Ulnar

Question 19

Why does miosis occur in horners syndrome?

Answer 19

Do to loss of sympathetic innervation to the iris dilator muscle causing constriction of the pupil.

Question 20

Why does ptosis and enophthammos occur in horners syndrome?

Answer 20

Superior tarsal muscle is made of SM fibres which normally elevate the upper eyelid.
The inferior tarsal also provides support when the eye is open.
This also causes narrowing of the palpebral fissure given a sunken appearance.

Question 21

Why does anhydrosis occur in horners syndrome?

Answer 21

Half on the face becomes flushed and dry.

Due to disruption in sympathetic supply to the sweat glands.