Pulmonary lymphangitic carcinomatosis is a metastatic lung disease characterised by diffuse spread of tumour to the pulmonary lymphatic system. When tumoral cells spread to the pulmonary lymphatic system and peri- Fig. 15 Bronchioloalveolar carcinoma. CT showed patchy distribution of areas with ground-glass opacification and areas with consolidation. Superimposed on these areas there is a reticular pattern corresponding to the thickening of the interstitium lymphatic interstitial tissue, interstitial thickening is seen on CT. The proliferation of these cells in combination with lymphatic dilatation contributes to this interstitial thickening (Fig. 8c) [21] .