PathCAL Lung Cancer Spread Flashcards
How does a tumour which arises in the respiratory epithelium of one of the more proximal bronchi develop?
- Ulcerate into the bronchus.
- Narrow the bronchus.
What are the signs and symptoms produced by ulceration of a tumour into the bronchus?
Haemoptysis
Cough
Breathlessness
What occurs in the distal lung tissue if the tumour narrows or blocks the bronchus?
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.
What is atelectasis?
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.
What shape is the collapsed lung tissue?
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.
What are the other consequences of bronchial obstruction?
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.
What are the symptoms produced from narrowing of the bronchus by tumour?
Pyrexia
Pain
Breathlessness
What is bronchiectasis?
Dilation of the bronchi
How can we spot squamous epithelium?
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.
How do lung carcinomas spread?
- Direct
- Lymphatics
- Blood
What are the common sites which a bronchial carcinoma might involve by local spread?
Pericardium Myocardium Brachial plexus Superior vena cava Vagus nerve
What is an effusion?
Collection of fluid in a serous cavity like the pleura (tumour spread to pleura)
What other disease process can give rise to pleural effusion in the context of lung cancer?
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.
What structure might a tumour in the apex of the lung press on to cause sever pain and weakness in the arm?
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.
Which group of lymph nodes would be the likely first port of call by metastasising cells from a bronchial carcinoma?
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.
Which lymph nodes does carcinoma turn up after the hilum lymph nodes?
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.
What technique might we use to diagnose metastases in cervical lymph nodes?
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.
What is lymphangitis carcinomatosis?
Very extensive lymphatic spread
What are typical sites for metastases from bronchial carcinoma?
Brain Liver Adrenal Lung Bone
How would metastases in bone present?
- 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.
What are non-metastatic effects?
Sometimes a bronchial carcinoma produces effects in distant organs without having metastasised to them.
What is the syndromes to which non-metastatic effects give rise?
Paraneoplastic syndromes
What is Cushing’s syndrome?
There might be stimulation of the adrenal cortex, with increased production of cortisol.
Paraneoplastic syndrome
What substance might a lung tumour produce that would give rise to Cushing’s syndrome?
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.
If the patient got disturbance of sodium metabolism, what hormone might the tumour cells be secreting?
The cancer cells synthesise and secrete ADH (antidiuretic hormone), also called vasopressin.
This circulates in the blood and acts on the kidney.
Both ACTH and ADH tend to be produced mainly by a certain histological type of lung cancer: which type is most commonly implicated?
Small cell lung cancer is the type that’s most prone to secreting hormones and other substances.
What might the tumour have produced to cause disturbance of calcium metabolism?
Parathyroid hormone (parathormone).
This stimulates osteoclasts to resorb bone, giving rise to hypercalcaemia.
Parathormone tends to be produced mainly by squamous cell carcinomas.
What are the symptoms of hypertrophic pulmonary osteoarthropathy?
Affects wrists and ankles
Pain
What is it called when distal parts of the fingers swell up in patients with lung cancer?
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.
What could result from non-metastatic involvement of the nervous system?
- Cerebellum
- Myelopathy
- Neuropathy
- Myopathy
What are the main sites of local spread of lung cancer outside the lung?
Hilar lymph nodes. Pleura, chest wall. Superior vena cava. Heart: pericardium, myocardium. Nerve: recurrent laryngeal, brachial plexus.
Overall signs and symptoms of lung cancer
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.
