MKSAP 3: Diffuse Parenchymal Lung Disease Flashcards
Describe how the terminology for diffuse parenchymal lung disease (DPLD) has changed and why compared to interstitial lung disease.
ILDs were named bc of abnormalities seen on biopsy of pulmonary interstitium but we now know that the disorders can also involve distal lung parenchyma, smaller airways, vasculature and pleura, thus DPLD.
Excludes pulmonary HTN and COPD, generally not infectious, most commonly present with dyspnea and cough and imaging findings are diffuse
Describe the classification of DPLDs
There are hundreds. Generally grouped into known or unknown causes.
Name the known causes of DPLD
Drug induced Smoking related Radiation Chronic aspiration Pneumoconioses Connective tissue diseases: RA, systemic sclerosis, polymyositis/dermatomyositis, other connective tissue diseases and hypersensitivity pneumonitis
Name the unknown causes of DPLD
Idiopathic interstitial pneumonias: IPF, AIP, COP
Sarcoidosis
Name the rare with well defined features of DPLD
LAM, chronic eosinophilic pneumonia, pulmonary alveolar proteinosis
LEFT OPEN FOR REVIEW OF THORACIC RAD TERMINOLOGY
LEFT OPEN FOR REVIEW OF THORACIC RAD TERMINOLOGY
LEFT OPEN FOR REVIEW of PATTERNS OF DISEASE associated with DPLD
LEFT OPEN FOR REVIEW of PATTERNS OF DISEASE associated with DPLD
Name the DPLDs associated with tobacco smoke and their patterns of presentation and imaging
Respiratory bronchiolitis - associated interstitial lung disease -> disease in active smokers who have imaging findings of centrilobular micronodules with respiratory bronchiolitis on biopsy
Desquamative interstitial pneumonia -> extensive, diffuse macrophage filling of alveolar spaces with predominant cough and dyspnea symptoms and bialteral ground glass opacities on CT imaging
Pulmonary Langerhans cell histiocytosis -> thin walled cysts with accompanying nodules often associated with pulm HTN
What is the primary cause of mortality in systemic sclerosis? And what medication is shown to give short term benefit to treat the lung disease?
Progressive pulmonary disease
Cyclophosphamide
What lung patterns can be seen in RA? What are possible treatments
Pleural disease, rheumatoid nodules, bronchitis, bronchiectasis, organizing PNA, bronchiolitis, and usual interstitial pneumonia.
Glucocorticoids and disease modifying agents
Define hypersensitivity pneumonitis. What are common causes? What are the CT findings and define treatment.
Result of an immunologic response to repetitive inhalation of antigens.
thermophilic actinomyces, fungi, bird droppings, baceterial, protozoal, animal, insect proteins or small molecular chemical compounds.
Presents within 48 hrs with fevers, flu like symptoms, couth, SOB. HRCT: ground glass opacities and cetrilobular micronodules that are upper and lower lobe predominant.
Remove exposure. Glucocorticoids used for patients with more severe symptoms and evidence of fibrosis.
Name some drugs associated with drug induced lung disease
Amiodarone Methotrexate Nitrofurantoin Busulfan Bleomycin
What is the timing and presentation of radiation induced parenchymal lung disease. What is the pathognomonic finding on imaging?
Acute radiation pneumonitis occurs 6-12 weeks after exposure. Cough, dyspnea, occasional fever and malaise.
HRCT: nonanatomic straight line demarcating involved vs uninvolved lung.
Name the DPLD with an unknown cause
IPF, NSIP, COP, AIP, sarcoidosis
What is the typical epidemiology, presentation and exam findings of IPF
Older individuals, rare in age < 50. Gradual onset of dyspnea, and cough over months to years. Dry inspiratory crackles and clubbing. PFTs with restrictive abnormality and reduced diffusing capacity.
Describe the typical findings of CT for IPF/UIP
Basal and peripheral predominant septal line thickening with traction bronchiectasis and honeycomb changes
What is the treatment for IPF?
Primarily supportive with optimization of fitness and oxygenation. Therapies used to include prednisone with or without azathioprine but these should be avoided because resulted in higher mortality.
Name the 2 most recent FDA drugs for IPF
nintednib - tyrosine kinase inhibitor known to block pathways that activate fibroblasts
pirfenidone - novel therapeutic agent that regulates TGF-b and TNF-a
Not curative
What is the only therapy that prolongs life in IPF?
Lung transplant
What are the similarities and differences b/w IPF and NSIP?
NSIP also predominantly affects lower lobes.
Unlike IPF, NSIP affects younger patients, strongly associated with connective tissue diseases especially systemic sclerosis.
Define organizing pneumonia vs COP
Organizing pneumonia is a patchy process that involves proliferation of granulation tissue within alveolar ducts, alveolar spaces and surrounding areas of chronic inflammation due to acute infections, autoimmune disorders like RA.
COP has this pattern but unknown etiology.
What is the typical timecourse and presentation of COP?
Present with symptoms that mimic CAP over 6-8 weeks but usually less than 3 months duration.
Bilateral diffuse alveolar opacities on CXR. Initial empiric treatment will fail.
What is the prognosis and treatment for COP?
Prognosis typically favorable and treatment is glucocorticoids with good response.
What is the presentation and prognosis of AIP?
Develops rapidly over days to weeks and results in progressive hypoxemic respiratory failure with bilateral alveolar opacities consistent with pulmonary edema and difficult to discern from ARDs. No clearly defined risk factors compared to ARDS.
