CT and MRI manifestations of primitive neuroectodermal tumors

LIUShu-han; FUGuo-li; YANYan

Abstract：Objective To investigate the CT and MRI manifestations of primitive neuroectodermal tumors (PNET) in or‐der to improve understanding of PNET .Methods A retrospective analysis of imaging data of 45 cases of PNET confirmed pathologically ,which included 29 males ,19 females ,with a mean age of 36 .4 years old ,was conducted in this work .Re‐sults PNET can be divided into central (cPNET ) and peripheral (pPNET ) types according to the occurrence at different parts .9 cases of cPNET exhibited the larger supratentorial tumor ,cystic degeneration and necrosis ,none or mild edema a‐round the tumor with clear boundary ,and relative uniform density /signal .CT showed that the density was equal or slightly higher than that of brain gray matter ,MRI T1 WI showed equal or slightly lower signal ,and T2 WI showed a slightly higher or mixed signal ,which may be associated with CSF spread .As for the 36 cases of pPNET ,the clinical manifestations were the obvious soft tissue mass ,with unclear boundary ,the density /signal was not uniform ,a little hemorrhage was visible ,and the calcification was rare .CT showed that the density was equal or slightly lower than that of the surrounding muscle and the MRI signal was complex ,without significant specificity .Tumor involved in the skeletal system can appeare as a large sheet of osteolytic bone destruction ,without periosteal reaction .Conclusion Although the imaging diagnostics of PNET is not taken as a gold standard ,it can determine the extent of lesions ,which is of importance for the preoperative staging ,postoperative evaluation ,and differential diagnosis .