pulmonary disorders
Overview of Idiopathic Interstitial Pneumonias
Diagnosis of Idiopathic Interstitial Pneumonias
High-resolution CT (HRCT) Pulmonary function tests Laboratory tests Sometimes lung biopsy Idiopathic interstitial pneumonia should be suspected in any patient with unexplained interstitial lung disease. Clinicians, radiologists, and pathologists should exchange information to determine the diagnosis in individual patients. Potential causes (see table) are assessed systematically. For maximum diagnostic yield, history should address the following criteria: Symptom duration Family history of lung disease, especially lung fibrosis History of tobacco use (because some diseases occur mostly among people who smoke or formerly smoked) Current and prior drug use Detailed review of home and work environments, including those of family members A chronologic listing of the patient's employment history, including specific duties and known exposures to organic and inorganic agents (see table), is obtained. The degree of exposure, duration of exposure, latency of exposure, and the use of protective devices is elicited. Chest x-rayis done and is typically abnormal, but findings are not specific enough to differentiate between the various types. Overview of Tests of Pulmonary Function None HRCT,which distinguishes airspace from interstitial disease, is the most useful test and is always done. It provides assessment of the potential etiology, extent, and distribution of disease and is more likely to detect underlying or coexisting disease (eg, occult mediastinal adenopathy, cancer, emphysema). HRCT should be done with the patient supine and prone and should include dynamic expiratory imaging to accentuate evidence of small airway involvement. Laboratory testsare done for patients who have clinical features suggesting a systemic rheumatic disease, vasculitis, or environmental exposure. Such tests may include antinuclear antibodies, rheumatoid factor, and other more specific serologic tests for systemic rheumatic diseases (eg, anti-cyclic citrullinated peptide [CCP], ribonucleoprotein [RNP], anti-Ro [SSA], anti-La [SSB], scleroderma antibody [Scl70], anti-Jo-1 antibody, myositis antibody panel). can help differentiate certain interstitial lung diseases, such as Sarcoidosis and Cryobiopsy,a technique that quickly freezes the lung tissue immediately prior to removal, is an aid to diagnosis of certain interstitial lung diseases. The tissue yield is higher than that of transbronchial biopsy but lower than surgical lung biopsy. Risks of the procedure include bleeding and pneumothorax. Transbronchial cryobiopsy can be considered as an alternative to surgical lung biopsy in centers with experience performing it and interpreting its results. is needed to confirm the diagnosis when the history and HRCT are nondiagnostic. Biopsy of multiple sites with Thoracoscopy and Video-Assisted Thoracoscopic Surgery (VATS) procedure is preferred. 