Week Six - Case Two Flashcards
what are the three colours of asbestos
white, blue and brown
what is the most dangerous colour of asbestos clinically and why
Blue is the most dangerous clinically. Its fibres are up to 50mm long, but only 1-2nanometres wide.
what happens when working with asbestos
the fibres are easily inhaled, but then became lodged in the lung. the properties of the fibre means they are particularly difficult to destruction by normal body mechanisms
how many years does it take between inhalation of the fibres and the development of mesothelioma
20-40 years
what sort of affect to smoking and asbestos fibres have
have a synergistic effect - thus the risk of bronchial carcinoma when having worked with asbestos and having smoked is greater than the sum of the two individual risks
what is asbestosis
this is fibrosis of the lung tissue secondary to exposure to asbestos
what sort of condition is asbestosis and when does it present
it is a progressive condition that will present 5-10 years after exposure
causes severe reduction in lung function and progressive dyspnoea.
what sort of respiratory pattern is asbestosis and what are the examination findings
Causes severe reduction in lung function and progressive dyspnoea. Restrictive pattern. There may also be finger clubbing, and bilateral end-inspiratory crackles.
what is seen on CXR with asbestosis
dark streaks, honeycomb appearance (honeycomb lung)
what sort of pattern will be on pulmonary function tests with mesothelioma
restrictive pattern
what does mesothelioma usually present with
pleural effusion and progresive dyspnoae
there may also be chest wall pain and ascites due to abdominal involvement
what is the journey of the mesothelioma
The tumour will begin as pleuritic nodules, which gradually grow and extend around the whole surface of the lung, and even into the fissures, hence the chest wall pain. Intercostal nerves and hilar lymph nodes may be invaded.
what is the medial survival of mesothelioma
around two years from presentation
is there a treatment for mesothelioma
no
what are pleural effusions broadly caragorised into
transudates and exudates based on the pleural fluid protein and LDH
what is the criteria for exudate effusion
Lights criteria was developed by Professor Light to identify exudative effusions and is highly sensitive. If any of the 3 criteria are met, then the effusion is defined as an exudate:
Pleural fluid protein / Serum protein >0.5
Pleural fluid LDH / Serum LDH >0.6
Pleural fluid LDH > 2/3 * Serum LDH Upper Limit of Normal
where do 90% of mesotheliomas arise
in the pleura but can develop in the peritoneum, pericardium and testes
what is the classic presentation of mesothelioma
Classic presentation is shortness of breath, chest pain and a pleural effusion. It can metastasise however more commonly progresses locally.
what are the 3 main subtypes of mesothelioma
The 3 main subtypes are epithelioid, sarcomatoid and mixed.
what subtype carries the worst prognosis
sarcomatoid
what is hypercalcaemia a sign of
squamous cell carcinoma
what can hypercalcaemia of malignancy result from
humoral hypercalcaemia of malignancy (characterised by tumour secretion of PTHrP
local osteolytic hypercalcaemia (characterised by local release of factors, including PTHrP,
by bony metastases that promote osteoclast differentiation and function);
calcitriol (1,25-dihydroxyvitamin D)-mediated hypercalcaemia (characterised by autonomous production of calcitriol [(1,25-dihydroxyvitamin D)] by lymphoma cells);
and ectopic hyperparathyroidism (characterised by tumour production of parathyroid hormone [PTH]), which is very rare.
what are the treatments for hypercalaemia of malignancy
Treatment options include intravenous bisphosphonates, denosumab, calcitonin, glucocorticoids (for calcitriol [1,25-dihydroxyvitamin D]-mediated hypercalcaemia), and calcimimetics (for ectopic PTH production).
in what percentage of cancer patients does hypercalcamia occur in
20-30%
what are the risk factors for hypercalcaemia of malignancy
non-metastatic malignancy
metastatic skeletal involvement
lymphoma
what are the key diagnostic factors for hypercalaemia of malignancy
presence of risk factors
history of malignancy
what are the other diagnostic factors for hypercalaemia of malignacy
normal physical exam
poor skin turgor and/or dry mucous membranes
confusion
fatigue
what are the first investigations to order for hypercalcaemia of malignancy
total serum calcium
serum ionised calcium
serum albumin
comprehensive metabolic panel
what are the differentials for hypercalaemia of malignancy
Primary hyperparathyroidism
Hyperthyroidism
Adrenal insufficiency
what does a urinary sodium value of higher than 40mmol suggest
syndrome of inappropriate ADH secretion
Urinary Sodium 62mmol (40 - 220)
- Urinary osmolality 319 mosm/kg (285 - 290)
Which is the most likely diagnosis?
small cell lung cancer
characteristically causes SIADH often quite severe and may be the cause of the presenting symptom.
in the SIADH the urine osmolatily is greater than the serum osmolality
A middle aged lady presents with mild dizziness due to vertigo and examination reveals grade 2 nystagmus. She is otherwise well and brain scanning is normal. Anti Hu antibodies are present. The most likely cause is:
Small cell lung cancer
Correct answer.
Antigens released by the tumour cause an immune response that attacks neurones.
A 25 year old man presents with haemoptysis and haematuria over 2 weeks. Which feature in his investigations would be most strongly associated with a diagnosis of vasculitis?
Strongly positive serum ANCA
The symptoms of haemoptysis and haematuria would make you concerned about a pulmonary renal syndrome such as vasculitis. Pulmonary vasculitis can cause a positive cANCA (GPA - granulomatosis with polyangitis).
A 46 year old alcoholic man is coughing up blood and retching. What feature in his clinical history is least associated with a respiratory cause of his symptoms?
Melaena
Correct answer.
This patients retching and alcohol intake supports a diagnosis of haematemesis and melaena is a strong predictor of GI bleeding.
A 70 year old lady with a 40-pack year history presents with a cough and haemoptysis. They report a 3 month history of lethargy and their skin has darkened without sun exposure. Investigations show:
- Temp 37.2
- Sats 93%
- HR 89
- RR 18
- BP 169/98
- Random blood glucose: 17 mmol/L
CXR shows lesions in the hilar region, what is the most likely diagnosis?
Small cell lung cancer
Due to ACTH secretion causing hyperpigmentation, HTN, impaired glucose tolerance & hilar region on CXR.
