PathCAL Lung Cancer Spread

Question 1

How does a tumour which arises in the respiratory epithelium of one of the more proximal bronchi develop?

Answer 1

• Ulcerate into the bronchus.

- Narrow the bronchus.

Question 2

What are the signs and symptoms produced by ulceration of a tumour into the bronchus?

Answer 2

Haemoptysis
Cough
Breathlessness

Question 3

What occurs in the distal lung tissue if the tumour narrows or blocks the bronchus?

Answer 3

The distal lung tissue collapses. If the bronchus is blocked, air can’t get into or out of the lung.
The air that’s in the alveoli already becomes resorbed into the blood and the lung tissue collapses.

Question 4

What is atelectasis?

Answer 4

Collapse of an area of the lung
This word is derived from Greek: ateles, meaning imperfect, and ektasis, meaning expansion; hence, imperfect expansion.
Incidentally, lots of other medical terms are derived from ektasis> For example, duct ectasia, in the breast.
The term pneumothorax, of course, generally refers to the whole lung, rather than to a part of it.

Question 5

What shape is the collapsed lung tissue?

Answer 5

Because the area the bronchus supplies is wedge-shaped and involves the overlying pleura, this governs the resultant shape of the area of collapse (a). We might well expect there to be inflammatory changes in the pleura: pleurisy.
This is similar to the rules that determine the shape of an infarct: the area an artery supplies is wedge-shaped. So if the artery is blocked, the infarcted area is the same shape as the tissue area supplied.

Question 6

What are the other consequences of bronchial obstruction?

Answer 6

It’s pneumonia.
When the lung collapses, the secretions produced in it persist but become stagnant, because they can’t be expelled by coughing.
Stagnant secretions anywhere in the body tend to become infected and then inflamed.
So the patient could well get a localised area of pneumonia.

Question 7

What are the symptoms produced from narrowing of the bronchus by tumour?

Answer 7

Pyrexia
Pain
Breathlessness

Question 8

What is bronchiectasis?

Answer 8

Dilation of the bronchi

Question 9

How can we spot squamous epithelium?

Answer 9

We know this because it’s several layers of cells thick and the cells at base, are relatively plump, while the cell towards the surface, are relatively flat. The cells are differentiating as they move upwards.

Question 10

How do lung carcinomas spread?

Answer 10

• Direct
• Lymphatics
• Blood

Question 11

What are the common sites which a bronchial carcinoma might involve by local spread?

Answer 11

Pericardium
Myocardium
Brachial plexus
Superior vena cava
Vagus nerve

Question 12

What is an effusion?

Answer 12

Collection of fluid in a serous cavity like the pleura (tumour spread to pleura)

Question 13

What other disease process can give rise to pleural effusion in the context of lung cancer?

Answer 13

Pneumonia
This could involve the pleura and give rise to inflammation of the pleura (pleurisy) and a pleural effusion.
This is why, if you withdraw fluid from a pleural effusion and send it for cytology, the report may say there are inflammatory cells present. It still doesn’t exclude the possibility that the patient has, in addition, lung cancer and it’s important to be aware of this: don’t just heave a sigh of relief and think all’s well.

Question 14

What structure might a tumour in the apex of the lung press on to cause sever pain and weakness in the arm?

Answer 14

The brachial plexus.
When the large nerve roots of the lower cervical and upper first thoracic nerves exit from the spine, they merge to form a large network of nerves called the brachial plexus.
If a tumour involves this, it may give rise to neurological symptoms and signs in the arm.
This causes severe pain in the arm.

Question 15

Which group of lymph nodes would be the likely first port of call by metastasising cells from a bronchial carcinoma?

Answer 15

Lung cancer tends to metastasis first to the hilar lymph nodes.
So if we suspect metastases, that’s certainly one place we should look for them.

Question 16

Which lymph nodes does carcinoma turn up after the hilum lymph nodes?

Answer 16

Bronchial carcinoma tends to turn up next in lymph nodes in one or other of the following sites:
-mediastinum
-neck
Indeed, small cell carcinomas often present with a mediastinal mass.

Question 17

What technique might we use to diagnose metastases in cervical lymph nodes?

Answer 17

The simplest way would be fine needle aspiration (FNA) and cytological examination of cells removed.
We could also biopsy the node.
We could also do a CT scan, although this would be more useful if we didn’t already know a lymph node was enlarged.

Question 18

What is lymphangitis carcinomatosis?

Answer 18

Very extensive lymphatic spread

Question 19

What are typical sites for metastases from bronchial carcinoma?

Answer 19

Brain
Liver
Adrenal
Lung
Bone

Question 20

How would metastases in bone present?

Answer 20

• Bone pain: this would be a common symptom. If a patient with cancer develops pain in a bone, it’s a cause for worry.
• Fracture: this is termed a pathological fracture, when the bone is abnormal.

Question 21

What are non-metastatic effects?

Answer 21

Sometimes a bronchial carcinoma produces effects in distant organs without having metastasised to them.

Question 22

What is the syndromes to which non-metastatic effects give rise?

Answer 22

Paraneoplastic syndromes

Question 23

What is Cushing’s syndrome?

Answer 23

There might be stimulation of the adrenal cortex, with increased production of cortisol.
Paraneoplastic syndrome

Question 24

What substance might a lung tumour produce that would give rise to Cushing’s syndrome?

Answer 24

ACTH (adrenocorticotrophic hormone).
The tumour cells secrete ACTH and this circulates in the blood and stimulates the cells of the adrenal cortex to secrete more cortisol.
In fact, the ACTH secreted by the neoplastic cells is not necessarily the same stuff secreted by the pituitary. It is often a variant with similar effects, namely stimulation of the adrenal cortex.

Question 25

If the patient got disturbance of sodium metabolism, what hormone might the tumour cells be secreting?

Answer 25

The cancer cells synthesise and secrete ADH (antidiuretic hormone), also called vasopressin.
This circulates in the blood and acts on the kidney.

Question 26

Both ACTH and ADH tend to be produced mainly by a certain histological type of lung cancer: which type is most commonly implicated?

Answer 26

Small cell lung cancer is the type that’s most prone to secreting hormones and other substances.

Question 27

What might the tumour have produced to cause disturbance of calcium metabolism?

Answer 27

Parathyroid hormone (parathormone).
This stimulates osteoclasts to resorb bone, giving rise to hypercalcaemia.
Parathormone tends to be produced mainly by squamous cell carcinomas.

Question 28

What are the symptoms of hypertrophic pulmonary osteoarthropathy?

Answer 28

Affects wrists and ankles

Pain

Question 29

What is it called when distal parts of the fingers swell up in patients with lung cancer?

Answer 29

Finger clubbing. It’s due to oedema of the soft tissues of the distal fingers.
Lung cancer isn’t the only cause of finger clubbing, but it’s one of the important ones to think about if you see a patient with finger clubbing.

Question 30

What could result from non-metastatic involvement of the nervous system?

Answer 30

• Cerebellum
• Myelopathy
• Neuropathy
• Myopathy

Question 31

What are the main sites of local spread of lung cancer outside the lung?

Answer 31

Hilar lymph nodes.
Pleura, chest wall.
Superior vena cava.
Heart: pericardium, myocardium.
Nerve: recurrent laryngeal, brachial plexus.

Question 32

Overall signs and symptoms of lung cancer

Answer 32

Haemoptysis: ulceration into bronchus.
Chest pain, fever, unwell: pneumonia, due to obstruction of a bronchus.
Weight loss: systemic feature of many tumours.
Lumps in neck: metastases in cervical lymph nodes.