Objective:To analyze CT and MRI findings of peripheral primitive neuroectodermal tumor(pPNET). Methods:The imaging and pathological features of pPNET in 8 cases were retrospectively analyzed.Results:The lesions were located in soft tissue, bone, nasal passages and viscera, and mainly presented as soft tissue masses with infiltrative growth pattern. CT showed inhomogeneous low density and MRI showed inhomogeneous iso-or hypointensity on T1 WI and iso-or hyperintensity on T2 WI, ill-defined demarcation, necrosis, cystic degeneration, no obvious calcification and heterogeneous enhancement(mild to moderate enhancement for solid components, no significant enhancement for cystic components). pPNET located in bones presented with osteolytic bone destruction and expansile lesion. No obvious tumor bone formation and periosteal reaction were found. Pathological fractures secondary to the tumors occurred. Conclusion:pPNET may present varying imaging features and can only be confirmed by pathological examination and immunohistochemistry. However, CT and MR imaging can clearly show the size of the lesion, internal structure, relationship with adjacent tissues, blood supply, the extent of violations and the distant metastasis, etc., which play key roles in the treatment and prognosis of pPNET. |