Respiratory Flashcards
What is the most significant cause of lung cancer?
Smoking
What is the most common type of lung cancer?
Non-small-cell lung cancer (80%):
Adenocarcinoma (40%)
Squamous cell carcinoma (20%)
Large-cell carcinoma (10%)
Other types (10%)
Small-cell lung cancer (SCLC) (20%)
What is mesothelioma?
Lung malignancy affecting mesothelial cells of pleura
Strongly linked to asbestos
Can take up to 45y to develop
What is the prognosis of mesothelioma?
Very poor
Chemo can improve survival, but is essentially palliative
Outline small-cell lung cancer
Contains neurosecretory granules that release neuroendocrine hormones
May be responsible for various paraneoplastic syndromes
Outline presentation of lung cancer
SOB
Cough
Haemoptysis
Finger clubbing
Recurrent pneumonia
Weight loss
Lymphadenopathy (often supraclavicular nodes 1st to be found)
List extrapulmonary manifestations of lung cancer
Recurrent laryngeal nerve palsy
Phrenic nerve palsy
SVC obstruction
Horner’s syndrome
Syndrome of inappropriate ADH (SIADH)
Cushing’s syndrome
Hypercalcaemia
Limbic encephalitis
Lambert-Eaton myasthenic syndrome
What is the association between lung cancer and recurrent laryngeal nerve palsy?
Presents with hoarse voice
Caused by tumour pressing on or affecting recurrent laryngeal nerve as passes through mediastinum
What is the association between lung cancer and phrenic nerve palsy?
Due to nerve compression
Causes diaphragm weakness and presents with SOB
What is the association between lung cancer and SVC obstruction?
Caused by direct tumour compression on SVC
Presents with facial swelling, difficulty breathing, distended neck and upper chest veins
Pemberton’s sign
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What is Pemberton’s sign?
Raising hands over head causes facial congestion and cyanosis
What is the association between lung cancer and Horner’s syndrome?
Triad of partial ptosis, anhidrosis and miosis
Caused by Pancoast tumour (in pulmonary apex) pressing on sympathetic ganglion
What is the association between lung cancer and SIADH?
Caused by ectopic ADH secreted by SCLC
Presents with hyponatremia
What is the association between lung cancer and Cushing’s syndrome?
Caused by ectopic ACTH secretion by SCLC
What is the association between lung cancer and Hypercalcaemia?
Caused by ectopic PTH secreted by squamous cell carcinoma
What is the association between lung cancer and Limbic encephalitis?
Paraneoplastic syndrome
SCLC causes immune system to make antibodies to tissues in brain (limbic system), causing inflammation
Associated with anti-Hu antibodies
List the symptoms of limbic encephalitis
Short-term memory impairment
Hallucinations
Confusion
Seizures
What is the association between lung cancer and Lambert-Eaton Myasthenic Syndrome?
Caused by antibodies against SCLC
Antibodies target and damage voltage-gated calcium channels on presynaptic terminals in motor neurones
List the symptoms of Lambert-Eaton Myasthenic Syndrome
Weakness in proximal muscles
Affect intraocular muscles causing diplopia (double vision)
Levator muscles in eyelid, causing ptosis
Pharyngeal muscles, causing slurred speech and dysphagia (difficulty swallowing)
Dry mouth, blurred vision, impotence, dizziness due to autonomic dysfunction
Outline the referral criteria for lung cancer
Suspected cancer- Recommend chest xray within 2wks to patients over 40y with signs of:
Clubbing
Lymphadenopathy (supraclavicular/persistent abnormal cervical nodes)
Recurrent/persistent chest infections
Raised platelet count (thrombocytosis)
Chest signs of lung cancer
Offer chest xray to patients over 40y with:
2+ unexplained symptoms in patients that have never smoked
1+ unexplained symptoms in patients that have smoked/had asbestos exposure
What are unexplained lung cancer guidelines as NICE guidelines suggest
Cough
SOB
Chest pain
Fatigue
Weight loss
Loss of appetite
What are the 2 key examination findings that automatically indicate an urgent chest xray for lung cancer?
Finger clubbing
Supraclavicular lymphadenopathy
Outline investigations for lung cancer
Chest xray 1st line
Staging CT scan- Chest, abdomen, and pelvis- Should be contrast-enhanced
PET-CT- Inject radioactive tracer- Identify metastases by highlighting areas of increased metabolic activity
Bronchoscopy with endobronchial US (EBUS)- Detailed assessment of tumour and US-guided biopsy
Histological diagnosis (biopsy)
List some potential findings of lung cancer on xray
Hilar enlargement
Peripheral opacity (visible lesion in lung field)
Pleural effusion (usually unilateral in cancer)
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