Fig. 3

Photomicrographs of a computed tomography-guided percutaneous lung biopsy specimen. (A) Hematoxylin and eosin staining. The main component is collagenous fibrous tissue, which contains abundant inflammatory cells. Inflammatory cells are diverse, including neutrophils and lymphocytes. The fibrous tissue is partially vitiligo-like. In the areas with abundant fibroblast-like spindle-shaped cells, there is a mat-like appearance and no atypia. Immunostaining for vimentin (B) and α-smooth muscle actin (C) were positive, and immunostaining for Anaplastic lymphoma kinase with a D5F3 antibody reveals a faint positive image in half of the spindle-shaped cells (D)