Lung Cancer Flashcards
What is the commonest cause of lung cancer?
Smoking
How does horners syndrome present?
Ptosis
Miosis - constricted pupil
Anhidrosis - loss of hemi facial sweating.
How does phrenic nerve palsy present?
Dyspnoea and orthopnoea
How does lung cancer originate?
Originates from epithelial cells in the respiratory tract. There are two main categories:
Small cell
Non-small cell
What do basal cells in the respiratory tract do?
Differentiate into other cells e.g goblet and ciliated.
What do club cells in the respiratory tract do?
Protect the bronchiolar epithelium.
What do neuroendocrine cells in the respiratory tract do?
Secrete hormones into the blood in response to neuronal signals.
What defines a malignant tumour?
A tumour able to break through the basement membrane.
> some detach metastasising.
What are some of the risk factors of lung cancer?
Smoking Radon gas Asbestos X-ray CT scans Genetics Air pollution
What sites are prone to metastasis of lung cancer?
Mediastinum and hilar lymph nodes due to proximity to the lungs.
Small cell carcinomas form from what cells?
Small immature neuroendocrine cells - not that common.
What are the four categories of Non-small cell lung carcinomas?
- Adenocarcinomas - form glandular structures that generate mucin.
- Squamous cell - produce keratin
- Carcinoid tumours - form from mature neuroendocrine cells.
- Large cell carcinomas - lack glandular and squamous differentiation.
Outline small cell carcinomas.
From small immature neuroendocrine cells. > associated with smoking. > develops near main bronchus. > grows fast and rapidly metastasizes. > Commonly large and in multiple sites. > can secrete hormones
What is meant by paraneoplastic syndrome?
The secretion of hormones from a tumour e.g release of ACTH by lung small cell carcinoma causing release of cortisol from the adrenal glands.
Excess cortisol =
Cushing’s syndrome
What hormones can small cell carcinomas of the lung release and what effect will that have?
ACTH - cushings, inc blood glucose.
ADH - inc water retention, inc blood pressure, oedema.
How can small cell carcinomas of the lung cause lambert-eaton myasthenic syndrome?
The small cell carcinoma secretes autoantibodies which destroy neurons in a type 2 hypersensitivty reaction, causing LEMS.
Squamous cell carcinoma usually affect where in the lung?
Central lung
Adenocarcinoma usually affect where in the lung?
Peripheral lung
Large cell carcinoma and bronchial carcinoma usually affect where in the lung?
Throughout the lung - both centrally and peripherally.
Pancoast tumour
Tumours of the upper lung that can compress the blood vessels and nerves there - formed from squamous cell carcinoma and adenocarcinoma.
What condition can pancoast tumours cause?
Horner’s syndrome
How can pancoast tumours cause Horner’s syndrome?
Pancoast tumours can damage:
Thoracic inlet
Brachial plexus - causes shooting arm pain and weakness.
Cervical sympathetic nerve
How does Horner’s syndrome present?
Constricted pupil
Drooping upper eyelid
Loss of ability to sweat on the same side of the body as the dysfunctional sympathetic nerve.
