Histopathological findings from video-assisted thoracoscopic surgery specimens of the left lung S9. (A) Macroscopic examination showing white-tinged lesions (arrow). (B-D) Microscopic histological examination demonstrating that the lung lesion is well demarcated (B) and consists of papillary growth of hyperplastic type II pneumocytes (C) with nuclear inclusion bodies (arrow in (D). Fibrous thickening of alveolar septa accompanied by increased elastic fibers can also be observed, leading to collapse of the alveolar space (C, D). (E) Elastica van Gieson staining confirming that elastic tissue fibers are evident.