Fig. 9.

Interstitial lung abnormality and lung squamous cell carcinoma in an 80-year-old man with rheumatoid arthritis. (a) Lung window image of CT scan obtained at level of liver dome shows subpleural fibrotic interstitial lung abnormality composed of reticulation and traction bronchiolectasis (arrowheads). Also note a 22-mm-sized nodule (open arrow) in left lung base. (b) Fused CT/PET image demonstrate high FDG uptake within left lower lung zone tumor (proved to be squamous cell carcinoma). (c) Low power magnification of lung demonstrating cystic dilation of distal small airways with rare fibroblast foci in the walls of the cysts consistent with UIP that are associated with patchy, moderate lymphoid infiltrates.