MRi maging features of pri mary pri mitive neuroectodermal tumors in the spinal cord and literature review

Objective To determine the MRi maging features of pri mary PNETin the spinal cord .Methods We retro-spectively reviewed MRi maging studies of 4 histologically and clinically confirmed pri mary PNETs in the spinal cord . Allfour patients underwent spinal MRstudy before and after injection of contrast agent preoperatively .Results The patients’ages ranged from13 to 46 years with a median of 26 .5 years . On MRi mage ,two tumors were located in the thoracic cordwith the other two in the conus medullaris and the cervicothoracic cord ,respectively . And focal mass effect was found inthree tumors while diffuse enlargement of the spinal cord was seen in one tumor . Among the four tumors ,cystic area waspresent and extended caudal fromthe tumor in only one case . They were all located at the center of the spinal cord with anill-defined margin and no apparent peritumoral edema . And all of them were hypo toisointense on T1-weightedi mages ,andhyperintense on T2-weighted i mages . After contrast , moderate or marked enhancement was found in three of them, whileslight enhancement in the rest one .Conclusion Pri mary PNETs of the spinal cord appear to be more commonin adults thanin children and may be intramedullary or exophytic or combinedintramedullary-extramedullary .In addition,they may be lo-cated at all levels of the spinal cord with the thoracic spinal cord and conus medullaris being the most common.But none oftheir MRi maging features was pathognomonic and the final diagnosis depends on surgical pathology .