Fig. 5

Histological findings of the pleural recurrence. a The tumor consists of a mixture of squamous and mucus-producing cells with solid cell sheets and gland formation (hematoxylin and eosin stain, ×400 objective lens magnification). b The mucus-producing cells that form the glands are Alcian blue-periodic acid–Schiff stain positive (periodic acid–Schiff stain, ×200 objective lens magnification). c Immunohistochemically, the tumor cells stain positive for cluster of differentiation (CD) 5 (×200 objective lens magnification)