CT,MRI and pathological analysis of peripheral primitive neuroectodermal tumors / 中华放射学杂志

ABSTRACT

Objective To analyze the CT and MRI appearances and to improve the knowledge of peripheral primitive neuroectodermal tumors(pPNETs).Methods CT or MRI were performed in 19 patients of pPNETs,which were confirmed by pathology.Results All the tumors were with unclear margin.Three cases occurred in intracalvarium,7 in the extremities,2 in the chest,4 in the abdomen,and 3 inside the spine.CT appearance of the tumors arising from soft tissue showed large,ill-defined,non-calcified mass and heterogeneous appearance with hypodense cystic areas.The tumors demonstrated heterogeneous contrast enhancement.The pPNETs arising from bone demonstrated extensive lytic lesion with large soft tissue mass,one case with newly-born bone and demonstrated heterogeneous contrast enhancement.The tumors demonstrated homogeneous intensity as muscle on SE T1WI and heterogeneous hyperintense signal on T2WI.Immunohistochemically,tumor cells showed positive for CD99,Syn,GFAP and negative for LCA.Conclusion The pPNETs show no characteristic manifestations on CT and MRI.However,CT and MRI can show the intra-tumor structures and the extent of the tumor very well,which is helpful in differentiating diagnosis,predicting resectability,detecting distant metastases and evaluating the response to treatment.