Airspace nodule

Figure 8 HRCT of a patient with LIP demonstrating cystic airspaces (A), ground glass opacities, thickened bronchovascular bundles, and centrilobular nodules (B). Abbreviations HRCT, high-resolution computed tomography LIP, l3miphocytic interstitial pneumtmia.

Cysts likely reflect airway obstruction caused by peribronchiolar lymphocytic infiltration (50). Peribronchovascular and subpleural cystic airspaces may be observed in up to two-thirds of patients and may progress over time (49,51,54). Honeycomb cysts are uncommon (5-20%) (49-51) but may develop in areas of prior consolidation (50). In a study of 14 patients of LIP who had serial CT scans, 9 improved, 4 worsened, and 1 remained stable (50). Many parenchymal abnormalities were reversible (50). However, cysts or architectural distortion either worsened or did not change on follow-up (50). Additional cysts often developed in areas where centrilobular nodules had been present on initial CT scans. 

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