Imaging, pathological, and proteomic findings in a 60-year-old man (patient P-08) who underwent bilateral lung transplantation for cystic_pLCDD. (A) Computed tomography shows round distinct thin-walled cystic airspaces in both lungs. Light microscopy reveals cysts derived from bronchioles and alveolar spaces (B; original magnification ×0.5, hematoxylin and eosin stain) associated with abundant eosinophilic extracellular amorphous deposits admixed with some plasma cells (C; original magnification ×30, hematoxylin and eosin stain). (D) Electron microscopy shows granular electron-dense deposits in a vessel wall (original magnification ×8000). (E) LC-MS/MS analysis after laser microdissection identifies immunoglobulin κ light chain variable VK1-8 and constant region as the main protein components of these tissue deposits (the proteins are listed according to their relative abundance using spectral count values from Proline software).