Desquamative Interstitial Pneumonia
DIAGNOSIS
Symptoms
- Gradual onset of dyspnea and dry cough over weeks or months3
- Cyanosis is a common presenting symptom1
- About 1/2 of patients with DIP will develop clubbing3
DIAGNOSTIC TESTS
- Pulmonary function tests
- DLCO is moderately decreased3,7
- Normal lung volumes or a mild restrictive abnormality3
- HRCT
- Features: ground-glass opacities, irregular linear or reticular opacities, sometimes cysts8
- Distribution: apicobasal gradient, peripheral predominance8
RB-ILD, hypersensitivity pneumonitis, sarcoidosis, and infections such as Pneumocystis carinii pneumonia may not be distinguishable from DIP on HRCT.3
- Surgical lung biopsy should be used in certain cases9
- Histopathology results featuring diffuse accumulation of macrophages in distal airspaces, mild interstitial fibrosis, mild chronic inflammation indicate a diagnosis of DIP8
- Bronchoalveolar lavage findings are not usually very specific1
- Features:
- Increased number of alveolar macrophages
- Large number of which have granules of smoker's-pigment consisting of intracellular yellow, gold, brown, or black smoke particulates3
- Features:
- Chest X-ray is not sensitive enough for detection of DIP and appears normal in 3%-22% of biopsy-proven cases3
- Features:
- Widespread patchy ground glass opacification
- Lower zone predilection
- Sometimes a peripheral predominance
- Features:
