Fig. 2

Histological findings and immunohistochemical studies. a Specimens of the lung tumor. b Specimens of the rectal lesion; 1. hematoxylin-eosin stain; 2. Napsin A expression (monoclonal antibody IP64); 3. TTF-1 expression (monoclonal antibody SPT24). Hypercolumnar, atypical, papillary-tubular cells proliferated and were histologically diagnosed as adenocarcinoma (a1, b1). Of both the lung specimens and the rectal specimen, some tumor cells contained regions that were be positive for napsin A regardless of the staining method (a2, b2). Almost all the tumor cells of both specimens were positive for TTF-1 (a3, b3)