Saturday, April 21, 2012

Differential Diagnosis #3: Bilateral Upper Lung Disease

Today's Daily Diff is bilateral upper lung disease. When evaluating chest x-rays, this pattern of disease is fairly common. Having a handy list of possible diagnosis can help you narrow down possible etiologies when framed in an appropriate clinical context. One handy mnemonic to help remember this differential is CASSETTE PRR:


DiseaseNotes
CCystic fibrosis
AAnkylosing spondylitis
SSarcoidosis 
SSilicosis
EEosinophilic granuloma / Langerhans cell histiocytosis Young male smokers
TTuberculosis
TTumors (metastases)
EEverything else
PPneumocystis Pneumonia (PCP)Immunocompromised
RRadiation fibrosis Head and neck cancers
RRheumatoid lung

In general, keep in mind that the upper lung zones have increased aeration and decreased perfusion relative to the lower lung zones due to the effects of gravity.


Silicosis
Source: Radiology Notes