Fig. 4
![Fig. 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12957-022-02662-7/MediaObjects/12957_2022_2662_Fig4_HTML.png)
Pathological findings with histological and immunocytochemical staining. a The tumor, with the formation of nests and cords of cells delimited from each other by connective tissue and vascular septations (hematoxylin-eosin × 200). b Tumor cells positive for chromogranin A (× 200). c Tumor cells positive for CD56 (× 200). d Tumor cells positive for synaptophysin (× 200)