Fig. 2

Operative imaging and pathological analysis of the new reported case. A intra-operative view of the tumor (labeled with asterisk) and the cricoid cartilage (labeled with arrow). B the gross specimen consisted of a 3.0- × 3.0- × 2.0-cm irregular, tan–pink mucosal lesion attached to the lower portion of the cricoid cartilage and the first three tracheal cartilages. C the chief cells (labeled with asterisk) show abundant and pale pink cytoplasm, and round nuclei with nucleoli. The peripheral sustentacular cells (labeled with arrow) are small and long with oval nuclei. Vascular sinusoids (labeled with triangle) are around the organoid pattern of “zellballen” (Hematoxylin–Eosin × 40), scale bar: 50 μm. D, E immunostaining analysis shows that chief cells are positive for chromogranin (D) and synaptophysin (E) in the cytoplasm (arrow, original magnification ×20), scale bar: 100 μm. F the peripheral sustentacular cells are outlined by S100 immunostaining (arrow, original magnification ×20). G intra-operative view of reconstruction of the defect with PTAPF (labeled with arrow), scale bar: 100 μm. H CT scans shows the reconstructed trachea with successful decannulation and no sign of tumor recurrence at the third year post-operatively