Fig. 2
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40792-020-00959-x/MediaObjects/40792_2020_959_Fig2_HTML.png)
Pathological findings of the autopsy samples. a Tumor composed of pleomorphic spindle cells with eosinophilic cytoplasm and polymorphonuclear cell infiltration. (Hematoxylin and eosin stain, × 20). b Tumor cells with squamous differentiation (arrow) in the regional lymph node. (Hematoxylin and eosin stain, × 20). c Cytokeratin AE1/AE3-positive lesion shows squamous differentiation (× 20). d PAX-8 sporadically positive in the atypical lesion (× 40). e Tumors in the lung reveal morphology of typical papillary thyroid carcinoma (arrowhead). (Hematoxylin and eosin stain, × 10)