Week 4 formative quiz questions Flashcards
Ultrasound is the only imaging modality that allows a site for drainage of a pleural effusion to be marked.
True – ultrasound imaging allows the fluid to be visualised and quantified with the patient in a seated position, and a marking can be made on the skin to show a safe site for needle insertion and fluid drainage. This cannot be done from a CXR because it is a 2D image, and a CT scan is performed in a supine position, so fluid would move as soon as the patient sits up!
Regarding Light’s Criteria: If the ratio of pleural fluid LDH/Serum LDH is greater than 0.6, the effusion is exudative.
True. Light’s Criteria help us decide whether an effusion is transudative or exudative, and therefore helps us determine the cause. The criteria (one or more required) for an exudative effusion are:
Pleural fluid protein/Serum protein >0.5
Pleural fluid LDH/Serum LDH >0.6
Pleural fluid LDH >2/3 the upper limit of the lab reference range for serum LDH
PET/CT shows metabolic activity of a lesion.
True – in addition to showing cross-sectional CT imaging, PET imaging involves injection of a radio-labelled glucose analogue. High uptake of glucose (i.e. a high metabolic activity) will therefore show up on the scan as a bright spot, and this may identify metastatic deposits (as cancers typically have high metabolic activity due to their rapid growth).
Lung cancer commonly metastasizes to the thyroid gland.
False – lung cancer commonly metastasizes to the adrenal glands.
Lung cancer has the highest mortality of any cancer, worldwide.
True – in the UK, it is the joint most common cancer (with breast cancer), but the mortality is significantly higher.
A pneumothorax can resolve without treatment.
True – not all pneumothoraces require treatment. Small pneumothoraces in well patients can simply be monitored, as the air will eventually be absorbed by the pleura.
Liver failure causes a transudative pleural effusion.
True – liver failure alters the protein composition of blood, and therefore alters the balance in oncotic pressure that maintains constant volume in the pleural cavity. This is therefore a process of fluid accumulation due to a change in filtration rather than inflammation, so causes a transudative effusion.
10% of smokers will develop lung cancer.
True – the risk of developing lung cancer is relative to consumption (quantified in terms of pack-years, where 20 cigarettes a day for 1 year is 1 pack-year) but there is no safe smoking threshold.
Adenocarcinoma of the lung is more likely to arise centrally.
False - bronchioalveolar epithelial stem cells transform and undergo atypical adenomatous hyperplasia, developing into adenocarcinoma in situ and then invasive adenocarcinoma of the lung. This epithelium is found in small airways, so this cancer is more likely to arise peripherally.
Patients with small cell lung cancer are only given radiotherapy to the brain if there are cranial metastases.
False – radiotherapy to the brain is given prophylactically (“prophylactic” treatment is anything that is given to prevent something) as it is known that SCLC frequently spreads to the brain.
Lung cancer which has spread to mediastinal lymph nodes can often be successfully surgically resected.
False – the finding of malignant lymph nodes on mediastinoscopy means a lung cancer is not surgically resectable.
Putting sterile talcum powder into the pleural cavity can help treat recurrent malignant pleural effusion.
True – this provokes an inflammatory reaction, which causes the visceral and parietal pleura to fuse, preventing recurrence of pleural effusion.
Very high dose radiotherapy can be used instead of surgery in some patients with lung cancer, to remove tumours by ablation.
True – SABR (stereotactic ablative radiotherapy) can have similar results to surgery in carefully selected patients with small tumours, who would not be fit for surgery. It involves a short course of very high dose radiation.
A pneumothorax which occurs without prior injury in a patient with a pre-existing lung condition is called a primary spontaneous pneumothorax.
False – primary pneumothoraces occur in people with no pre-existing lung disease. The description above is of a secondary spontaneous pneumothorax.
Patients with mesothelioma are entitled to compensation.
True – it is an occupational lung disease, and patients (or their families) are entitled to compensation.
Small cell lung cancers are much faster-growing than non-small-cell lung cancers.
True – non-small-cell lung cancers have an average doubling time of 129 days, whereas in small cell lung cancers it is 29 days.