Fig. 2

Histopathological examination: a heterotypic cells could be seen in the submucosa hyperplastic lymphoid tissue, with nest infiltration and growth. The nuclear atypia is obvious, and the nuclear division is easy to see. Its epithelial layer was intact. However, the classification is still unclear; b positive immunohistochemical staining for AE1/AE3, in accordance with epithelial carcinoma; c positive immunohistochemical staining for P40, consistent with squamous cell carcinoma; d positive immunohistochemical staining for P63, in line with squamous cell carcinoma