Abstract：Objective: To analyze the CT imaging and clinicopathologic features of the pediatric peripheral primitive neuroectodemal tumor(pPNET). Methods: CT imaging of 6 cases with pathologically proven pPNET was retrospectively reviewed, among which 4 cases performed enhanced CT scan. Results: Of all cases, 6 lesions were located in the chest wall(n=2), retroperitoneum(n=2), palm dorsal(n=1), and pelvis(n=1). The pPNET in soft tissue appeared as a large, ill-defined mass, with(n=4) or without(n=2) bony invasion, and inhomogeneous density with cystic degeneration, necrosis and internal separations. Most tumors showed heterogeneous enhancement. All patients underwent surgical resection. Histopathological examinations were performed in all cases. Conclusion: Pediatric pPNET are rare with no typical imaging findings. CT is helpful in the displaying location, size, source, blood supply and the involvement of neighbour tissues of tumors. The diagnosis of pPNET should be considered in young patients with a large, ill-defined, soft-tissue mass containing areas of cystic degeneration, necrosis and internal separations. The presence of Homer-Wright rosettes or immunohistochemical expression of CD99 supports the diagnosis of pPNET.
2015, Vol. 26 
