Lung Pathology Flashcards
In what percentage of patients does progressive TB occur?
Less than 10% of all TB patients, usually immunosuppressed
What are some DDx of bilateral hilar enlargement?
Sarcoidosis
Lymphoma
TB
Metastasis
Other infections - fungal
What is honeycomb lung?
Irreversible end-stage manifestation of a large number of interstitial inflammatory and proliferative lung diseases
Poor prognosis
What is the pathogenesis of an exudate?
Altered permeability of or damage to the capillaries surrounding space
What are some non-infectious causes of pleuritis?
Trauma
Infarction
Connective tissue disorders: eg RA or lupus
Uraemia
Tumour
Radiation effect
What is a common cause of mesothelioma?
Asbestos
What is sarcoidosis?
It is a multisystem inflammatory disease of unknown etiology that manifests as noncaseating granulomas, predominantly in the lungs and intrathoracic lymph nodes
What is a common first presentation of mesothelioma?
Pleural effusion
What type of TB typically occurs at the apex of the lung?
Secondary TB
What are common causes of interstitual lung disease?
Idiopathic
Occupational/environmental exposure
Drugs
What is secondary TB?
Reactivation of a dormant focus of primary TB
or a new infection
What is the pathophysiology of mesothelioma?
Small fibres in the alveolar causes chronic stimulation > tumour develops
What is granulomatous inflammation?
Nodular clusters of macrophages +/- giant cells
What is the commonest cause of non-necrotising granulomas?
Sarcoidosis
What are differentials for granulomatous inflammation?
TB
Sarcoid
Lymphoma
What is Gohn’s complex?
Gohn focus - TB lesion in the lung parenchyma
TB Lesion in a draining LN
What must you do before treating sarcoidosis?
Exclude infective causes as steroids will likely exacerbate the infection
What is the prognosis of mesothelioma?
Average survival from onset of symptoms is 12-15 months
Mortality is 100%
What causes a chylous effusion?
High lymphocyte count - TB, lymphoma
How much fluid accumulation consitutes a pleural effusion?
>15mL
Typical presentation of interstitial lung disease?
Slow, increasing SOB
Dry cough
How do you differentiate adenocarcinoma with mesothelioma?
IHC staining
What is the difference between a transudate and exudate?
Transudate is lower in protein
What is the pattern of location of sarcoidosis?
Enlarged lymphadenopathy at the hilum
Bilateral granulomatous inflammation of lungs
What is the main differential for mesothelioma?
Adenocarcinoma
What are the three stages of ARDS and how do they appear microscopically?
Acute - Alveolar spaces with hyaline membranes and oedema
Organising - Pneumocyte hyperplasia and interstitium inflammation and reactive fibrosis
Chronic - Denser fibrosis and microscopic cysts
How does mesothelioma appear macroscopically?
Numerous small nodules covering the serosa, fuse and form diffuse thickening.
Massive encase of viscera often causing obliteration of pleura or peritoneal cavity
How does mesothelioma appear microscopically?
Epithelioid type with tubulopapillary structures
Sarcamatoid type with spindle cells
Tumour cells have enlarged nuclei, prominent nucleoli and hyperchromasia
What is the cell surface marker for mesothelioma?
Calretin
