Lymphocytic interstitial pneumonia: thin-section CT findings in 22 patients.

PURPOSE: To assess the thin-section computed tomographic (CT) findings of lymphocytic interstitial pneumonia. MATERIALS AND METHODS: The study included 22 patients (five men, 17 women; age range, 24-83 years; mean age, 50 years) with biopsy-proved lymphocytic interstitial pneumonia. The CT scans were obtained by using 1-3-mm collimation and reconstructed by using a high-spatial-frequency algorithm. RESULTS: The predominant abnormalities consisted of areas of ground-glass attenuation and poorly defined centrilobular nodules present in all 22 patients and subpleural small nodules seen in 19 patients. Other common findings included thickening of bronchovascular bundles (n - 19), interlobular septal thickening (n = 18), cystic airspaces (n = 15), and lymph node enlargement (n = 15). Less common findings included large nodules, emphysema, airspace consolidation, bronchiectasis, architectural distortion, honeycombing, and pleural thickening. CONCLUSION: Lymphocytic interstitial pneumonia is characterized by the presence of ground-glass attenuation, poorly defined centrilobular nodules, and thickening of the interstitium along the lymphatic vessels. Lymph node enlargement is more common than previously recognized; it was seen in 68% of patients.