Chest malignancy signs, causes and differentials

Question 1

What non-metastatic (paraneoplastic) manifestations of malignant lung cancer?

(The symptoms that the tumour can have on the body beyond red flag symptoms and the effects of metastases)

Answer 1

Fibrosis:
Finger clubbing

Bone complaints:
Hypertrophic pulmonary osteoarthropathy - pain in knees and elbows
(new bone forming in the periosteum in forearms and lower legs)

Hormone syndromes:
Hyperparathyroidism - hypercalcaemia
(secretion of PTH by an squamous tumour)

Cushing syndrome
(ACTH secretion by the small cell tumour)

Syndrome of inappropriate release of ADH
(SIADH with hyponatremia: classic cause is small cell lung carcinoma)

Neuromyopathies:
Eaton lambert syndrome (NO AcH:a neuromyopathypathy, prevents ACh release at the NMJ)

Myasthenia gravis (INSENSITIVE TO AcH: muscle weakness prevents ACh acting at the NMJ)

Peripheral neuropathy (loss of feeling)

Dementia

Cerebellar syndrome (ataxia, poor coordination)

Question 2

What are the causes of bronchial carcinoma?

Answer 2

Tobacco smoke - biggest cause 95% (2nd hand smoking increases risk by 25%)

Ionising radiation

Asbestos - construction work

Fibrosing alveolitis

Arsenic

Chloromethyl ethers

Chromium

Nickel

Polyaromatic hydrocarbons

Vinyl chloride

Question 3

What is the most common primary pleural carcinoma referred to as?

Answer 3

Mesothelioma

Question 4

Where do secondary lung metastases originate from? (Four organs)

Answer 4

Breast

Kidney

Bladder

Testis

Question 5

What is the primary cause of mesothelioma?

Answer 5

Asbestos exposure

Question 6

What are the two basic categories of primary lung cancers?

Answer 6

1. small cell lung cancers - 24%
   - named because they look like small cells on their histopathology slides, very little cytoplasm and a large nucleus

2 . non-small cell lung cancers - 76%

• squamous carcinoma have a large, flattened cell type on their histopathology slides

Question 7

How are small cell lung cancers different to non small cell lung cancers?

Answer 7

Small cell cancers are a homogenous group

Non small cell cancers are a mixture:
Squamous 
Adenocarcinoma 
Large cell 
Other

Question 8

What is the most common type of non small cell carcinoma?

Answer 8

Squamous cell carcinoma - 48% of all non small cell

Adenocarcinoma is 2nd most common - 13%
(Large cell is the 3rd most common - 10%)

Question 9

What are the signs of bronchial cancer?

Answer 9

Facial swelling

Cough

Haemoptysis

Chest pain

Dyspnoea

Stridor - due to narrowing of the airways

Hoarseness - tumour invading the mediastinum left side can damage the left recurrent laryngeal nerve

Weight loss

On examination:

Finger clubbing

Lymphadenopathy - enlarged lymph nodes

Chest movement asymmetry

Consolidation

Fluid - effusion

Hepatomegaly - metastases

Neuropathy - non metastatic presentations

Question 10

What is pancoast syndrome?

Answer 10

A supraclavicular fossa that is filled in, a tumour arising at the apex of the lung growing upwards.

This will grow in to the brachial plexus, causing:

1. Pain radiating down inner arm
2. Horner’s syndrome; pupil on that side will be smaller, and may have ptosis and a dry eye - sympathetic innervation to the eye comes from T1 and reaches brachial plexus before travelling up carotid artery to eye.

Question 11

What is the possible presentation of a lung cancer growing in the mediastinum?

Answer 11

Superior vena caval obstruction:
compromises venous return from head, upper mediastinum and arms

Presents with:
- Facial and hand swellings; episodic and then constant

• Headaches

Question 12

What are the neurological signs of lung cancer metastasis?

Answer 12

Focal/general neurological signs: 
Dysphagia
Dysphonia
Dysphasia
Visual field defects
Hemiparesis
Decreased GCS
Respiratory depression
Muscle weakness

Causes:
Cerebral haemorrhage - raised ICP
Metastasis

Question 13

What are the differentials for suspected bronchial carcinoma?

i.e will also cause shadowing on the lung in a cxr

Answer 13

TB

Pneumonia

Lung metastases from other primary

Benign lung tumor

Rare conditions like wegener’s granulomatosis

Question 14

One of the paraneoplastic syndromes in lung cancer is hyperparathyroidism:

What are the signs of hypercalcaemia?

Answer 14

Bones, stones, groans and moans:

Bone pain

Renal stones

Abdominal groans

Psychiatric moans

Question 15

What is the life expectancy of small cell lung cancer without treatment?

Answer 15

6 weeks

Chemotherapy generally only increases this to 12 weeks

Small-cell carcinoma is normally palliative (only 1-2% is curative)

Question 16

Lung cells change in the progression to lung cancer, when are they called carcinoma in situ?

Answer 16

This is the stage before cancer, when the cells have severe dysplasia.

Normal cells -> Hyperplasia -> Mild dysplasia

• > Severe dysplasia (carcinoma in situ)
• > Cancer; invasive, breaks through basement membrane

Question 17

How does non small cell carcinoma cause hypercalcaemia?

Answer 17

The tumour begins to produce and release parathyroid-related protein which acts like PTH, which acts on the kidney, gut and bones

Common causes:
Squamous cell lung cancer
Breast cancer
Multiple myeloma
Cholangiocarcinoma

Question 18

What is asbestosis?

Answer 18

A chronic lung condition associated with lung fibrosis caused by chronic exposure to asbestos.

MOA =
1.Asbestos fibres deposit at alveolar duct bifurcations and cause macrophage-driven inflammation, with release of IL-beta and TNF

2. The fibres are cleared via the lymphatic drainage and pleural cavities. However the fibres have initiated the tissue immune response and this cause fibrosis .
3. Thickening and fibrosis of the visceral pleura occurs in a dose dependant manner, this leads to fusion with the parietal pleura.

(Not the same as mesothelioma or benign plaques caused by asbestos, mesothelioma isn’t dose-dependant)

Question 19

What are the signs and symptoms of asbestosis?

Answer 19

Exertional dyspnoea

Cough

Wheeze

Chest pain

Basal crackles

Clubbing - only advanced cases

A NON-SPECIFIC INSIDIOUS PRESENTATION

Question 20

What is mesothelioma?

Answer 20

An aggressive tumour of the mesothelial cells that most often (90%) occurs in the pleura, it has a poor prognosis.

Latency period can be to 45 years

Question 21

What are the signs and symptoms of mesothelioma?

Answer 21

Chest pain

Dyspnoea

Weight loss

Finger clubbing

Recurrent pleural effusions

Signs of metastases:
Lymphadenopathy 
Hepatomegaly
Bone pains
Abdominal pain and obstruction