Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40792-020-00957-z/MediaObjects/40792_2020_957_Fig1_HTML.png)
a Macroscopic appearance of the opened esophagus and stomach shows an ulcerative and infiltrative type tumor in the middle thoracic esophagus. Histopathologic examination of the resected specimen shows moderately differentiated squamous cell carcinoma (b hematoxylin and eosin stain, ×100), with a focal basaloid component (square, c × 4 and d × 100). Immunohistochemical examinations show that the primary tumor cells are positive for e p63and f p40 (× 100)