pulmonary disorders
Nonspecific Interstitial Pneumonia
Diagnosis of Nonspecific Interstitial Pneumonia
High-resolution CT (HRCT) Surgical lung biopsy The diagnosis of nonspecific interstitial pneumonia should be considered in patients with unexplained subacute or chronic cough and dyspnea. Diagnosis requires HRCT and always requires confirmation by lung biopsy. NSIP is a diagnosis of exclusion that requires careful clinical review for possible alternative disorders, in particular systemic rheumatic disorders, hypersensitivity pneumonitis, and drug toxicity. Chest x-rayprimarily shows lower-zone reticular opacities. Bilateral patchy opacities are also possible. HRCTfindings include bilateral patchy ground-glass attenuation, irregular lines, and bronchial dilation (traction bronchiectasis), generally with a lower lung zone distribution. Subpleural sparing is possible. Honeycombing is rare. Bronchoalveolar lavagefluid has an increased percentage of lymphocytes in more than half of patients, but this finding is nonspecific. Surgical lung biopsyis required for a diagnosis of NSIP. Histologically, most patients have some degree of fibrosis. The main feature of NSIP is temporally homogenous inflammation and fibrosis, as opposed to the heterogeneity in usual interstitial pneumonia. Although the changes are temporally uniform, the process may be patchy, with intervening areas of unaffected lung. 