Week Six - Case Two

Question 1

what are the three colours of asbestos

Answer 1

white, blue and brown

Question 2

what is the most dangerous colour of asbestos clinically and why

Answer 2

Blue is the most dangerous clinically. Its fibres are up to 50mm long, but only 1-2nanometres wide.

Question 3

what happens when working with asbestos

Answer 3

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

Question 4

how many years does it take between inhalation of the fibres and the development of mesothelioma

Answer 4

20-40 years

Question 5

what sort of affect to smoking and asbestos fibres have

Answer 5

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

Question 6

what is asbestosis

Answer 6

this is fibrosis of the lung tissue secondary to exposure to asbestos

Question 7

what sort of condition is asbestosis and when does it present

Answer 7

it is a progressive condition that will present 5-10 years after exposure

causes severe reduction in lung function and progressive dyspnoea.

Question 8

what sort of respiratory pattern is asbestosis and what are the examination findings

Answer 8

Causes severe reduction in lung function and progressive dyspnoea. Restrictive pattern. There may also be finger clubbing, and bilateral end-inspiratory crackles.

Question 9

what is seen on CXR with asbestosis

Answer 9

dark streaks, honeycomb appearance (honeycomb lung)

Question 10

what sort of pattern will be on pulmonary function tests with mesothelioma

Answer 10

restrictive pattern

Question 11

what does mesothelioma usually present with

Answer 11

pleural effusion and progresive dyspnoae

there may also be chest wall pain and ascites due to abdominal involvement

Question 12

what is the journey of the mesothelioma

Answer 12

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.

Question 13

what is the medial survival of mesothelioma

Answer 13

around two years from presentation

Question 14

is there a treatment for mesothelioma

Answer 14

no

Question 15

what are pleural effusions broadly caragorised into

Answer 15

transudates and exudates based on the pleural fluid protein and LDH

Question 16

what is the criteria for exudate effusion

Answer 16

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

Question 17

where do 90% of mesotheliomas arise

Answer 17

in the pleura but can develop in the peritoneum, pericardium and testes

Question 18

what is the classic presentation of mesothelioma

Answer 18

Classic presentation is shortness of breath, chest pain and a pleural effusion. It can metastasise however more commonly progresses locally.

Question 19

what are the 3 main subtypes of mesothelioma

Answer 19

The 3 main subtypes are epithelioid, sarcomatoid and mixed.

Question 20

what subtype carries the worst prognosis

Answer 20

sarcomatoid

Question 21

what is hypercalcaemia a sign of

Answer 21

squamous cell carcinoma

Question 22

what can hypercalcaemia of malignancy result from

Answer 22

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.

Question 23

what are the treatments for hypercalaemia of malignancy

Answer 23

Treatment options include intravenous bisphosphonates, denosumab, calcitonin, glucocorticoids (for calcitriol [1,25-dihydroxyvitamin D]-mediated hypercalcaemia), and calcimimetics (for ectopic PTH production).

Question 24

in what percentage of cancer patients does hypercalcamia occur in

Answer 24

20-30%

Question 25

what are the risk factors for hypercalcaemia of malignancy

Answer 25

non-metastatic malignancy
metastatic skeletal involvement
lymphoma

Question 26

what are the key diagnostic factors for hypercalaemia of malignancy

Answer 26

presence of risk factors
history of malignancy

Question 27

what are the other diagnostic factors for hypercalaemia of malignacy

Answer 27

normal physical exam
poor skin turgor and/or dry mucous membranes
confusion
fatigue

Question 28

what are the first investigations to order for hypercalcaemia of malignancy

Answer 28

total serum calcium
serum ionised calcium
serum albumin
comprehensive metabolic panel

Question 29

what are the differentials for hypercalaemia of malignancy

Answer 29

Primary hyperparathyroidism
Hyperthyroidism
Adrenal insufficiency

Question 30

what does a urinary sodium value of higher than 40mmol suggest

Answer 30

syndrome of inappropriate ADH secretion

Question 31

Urinary Sodium 62mmol (40 - 220)

• Urinary osmolality 319 mosm/kg (285 - 290)

Which is the most likely diagnosis?

Answer 31

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

Question 32

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:

Answer 32

Small cell lung cancer
Correct answer.
Antigens released by the tumour cause an immune response that attacks neurones.

Question 33

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?

Answer 33

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).

Question 34

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?

Answer 34

Melaena
Correct answer.
This patients retching and alcohol intake supports a diagnosis of haematemesis and melaena is a strong predictor of GI bleeding.

Question 35

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?

Answer 35

Small cell lung cancer
Due to ACTH secretion causing hyperpigmentation, HTN, impaired glucose tolerance & hilar region on CXR.