Intraluminal (Intra-alveolar) Diffuse Fibrosis of the Lung
The present communication describes the morphology, etiology and mechanisms of intraluminal (or intra-alveolar) diffuse fibrosis of the lungs. Pulmonary fibrosis is the end-stage of tissue injury in the lungs and is usually non-specific. The determination of its original cause is difficult, but intraluminal diffuse fibrosis with loose stroma is quite unique and characteristic. In addition to paraquat lungs, we herein show that radiation pneumonitis, infarction, and some forms of bronchiolitis obliterans may cause this type of fibrosis. It is speculated that intraluminal diffuse fibrosis is the result of severe alveolar epithelial damage occurring diffusely and continuously, followed by edema and organization of the alveoli.