primary spinal cord tumors represent 4.5% of all cns neoplasms and the most common tumor type is meningioma ( 24.4% ) ( 1 ) . spinal meningiomas are more common in elderly patients , mean age varying from 56 up to 66 years in different studies ( 3 - 6 ) ; in sandalcioglu et al.s study , the age range was 17 to 88 years in a review of 131 patients ( 3 ) . spinal meningiomas are slow growing tumors and therefore , they lead to symptoms only when they reach a considerable size to compress the spinal cord , causing local pain ; however , in a significant number of patients , the diagnosis is not confirmed until neurologic deficits or gait disturbances become evident ( 3 ) . intraspinal meningiomas are most commonly located in thoracic region , followed by cervical and lumbar areas ( 7 - 9 ) . there are only few reports in the literature describing postoperative outcome of spinal meningiomas ( 10 - 14 ) . in addition , little is known about the different prognostic factors influencing recovery , especially the influence of histopathologic subtype ( 11 ) . this study is carried out to evaluate the effect of some of these factors specially the effect of histopathologic subtype on the postoperative outcome . all patients with spinal meningioma referred to shohada hospital , tehran , iran for surgical resection of spinal meningioma between october 1998 and january 2012 were included in this study . the patients records including age , sex , address , history , radiologic data , operative notes , tumor location and pathology reports were registered retrospectively . the results of 8 - 120 months post - operative follow up were then classified according to frankel classification ( table 1 ) . all patients had plain x - rays and ct - scan of spine and only 14 ( 36% ) had mri for localization of tumor . three pathologists studied histologic slides independently and diagnoses were made according to who 2007 criteria . statistical analyses were performed using spss software version 11.0 . using t - test and fisher s exact test , we compared the results . a total number of 39 patients with spinal meningioma were referred to shohada hospital and underwent neurosurgical resection . twenty - five were women ( 64% ) and 14 were men ( 36% ) . histological classification according to who criteria was as follows : 34 cases ( 87% ) were who grade i , from which 15 cases ( 38% ) were psammomatous , 7 cases ( 18% ) were meningothelial , 9 cases ( 23% ) were transitional and 3 cases ( 8% ) were fibroblastic . five patients ( 13% ) were grade ii , 3 of which ( 7.5% ) had clear cell appearance and the remaining 2 ( 5.5% ) had chordoid appearance ( figures 1 and 2 ) . a , meningothelial ; b , fibroblastic ; c , chordoid ; d , psammomatous . there was no significant difference in preoperative neurologic signs according to frankel classification between different histological subtypes . table 2 shows the summary of pre- and post - operative neurologic deficits in 39 patients with spinal meningiomas . seventy - nine percent of patients had grade d and e , 19% grade c and 2% had grade b. postoperatively 82% improved or not changed and 18% worsened . one patient with psammomatous cervical meningioma with frankel grade c had severe grade b signs after surgery . following surgery , pain was relieved in all patients ; bladder dysfunction ( in one case ) was cured . paresthesia remained only in one out of ten patients . from 8 patients who were unable to walk ( group b or c ) , five cases remained at the same status ( group b or c ) postoperatively from which two cases were psammomatous and three cases were who grade ii meningioma . when comparing surgical outcome between different histologic subtypes , we observed that 6 out of 15 patients with psammomatous meningioma ( 40% ) had worsened results or persistent functional deficit of grade c or worse . all of five cases of who grade ii meningioma worsened after surgery or remained unchanged in grade c. these are significantly different from remaining 19 cases of who grade i meningioma ( non - psammomatous ) , all of which ( 100% ) showed improved results or not changed post - operatively , remaining in grade d or e ( p = 0.003 and p < 001 ) ( tables 3 and 4 ) . good outcome means frankel grades d and e ; poor outcome means group b and c. the mean age of patients with good postoperative outcome was 51.8 while the mean age of patients with poor outcome was 51.5 , so the age does not affect the outcome ( p = 0.34 ) . seven out of 11 patients with poor outcome ( 63.6% ) and 18 of 28 patients with good outcome ( 64% ) were women : sex had no significant influence on the outcome ( p = 0.99 ) . cervical location of tumor was seen in 5 out of 11 patients with poor outcome ( 45.5% ) and in 3 out of 28 patients with good outcome ( 10.7% ) : cervical location had significant influence on the outcome ( p = 0.027 ) . the mean tumor size was 2.7 cm in greatest dimension in patients with poor outcome and 2.6 cm in cases of good outcome ( p = 0.40 ) . five of the poor - outcome cases have been reported to have adhesion during surgery and incomplete removal ( 45% ) , while two of the others have this condition ( 7% ) ( p = 0.012 ) . meningiomas are primary tumors of spines , arisen from the arachnoid cap cells of the meninges ; they constitute about 1.2% of all cns meningiomas ( 3 ) . in our study , spinal meningiomas constitute 7.7% of cns meningiomas ; this could be due to the fact that shohada hospital is a referral center for difficult cases of spinal tumor surgery . psammomatous subtype and grade ii cases had poor postoperative outcome while the other subtypes of who grade i had good outcome in our study . in schaller study ( 11 ) , psammomatous subtype had a less favorable outcome compared with other subtypes ; in roux et al . study ( 6 ) , histological subtype did not seem to have any influence on the postoperative outcome . ( 6 ) , klekamp and samii ( 5 ) , haegelen et al . ( 4 ) and sandalcioglu et al . ( 3 ) all revealed significantly higher incidence of meningioma in women as in our study that revealed a female to male ratio of 1.8 to 1 . in the study of roux et al . ( 6 ) , as in our study sex had no influence on the prognosis . the average age of patients varies between 56 and 66 in studies of roux et al . ( 6 ) and haegelen et al . ( 4 ) respectively ; in our study the average age was 51.6 and prognosis was not influenced by increasing age . in schaller study age less than 60 years was correlated with a good outcome ( 11 ) . in sandalcioglu study ( 3 ) elderly patients proved to harbor an increased risk for surgical morbidity . in our study cervical location of the tumor was related with poor outcome in our study ; in schaller study ( 11 ) , tumor location below c4 seemed to be correlated with a good outcome ; in other studies ( 3 , 6 , 10 , 12 ) no correlation was found . incomplete removal of the tumor was seen in about half of the cases with poor outcome and 7% of the other group . since 80% of the incompletely removed tumors of the first group are of psammomatous subtype , it seems that incomplete removal of the tumor may be the reason of poor outcome in psammomatous subtype in comparison with other subtypes of who grade i , although further studies with larger sample size are needed to confirm this result . spinal meningioma of who grade i with psammomatous subtype are associated with less favorable postoperative neurologic outcome than other subtypes , with results closer to cases of who grade ii . incomplete resection of spinal meningioma occurs more frequently in psammomatous subtype and cases of who grade ii and trying to complete resection may cause additional neurological damage . cervical location is another factor that seems to have a negative correlation with a good outcome . psammomatous subtype and grade ii cases had poor postoperative outcome while the other subtypes of who grade i had good outcome in our study . in schaller study ( 11 ) , psammomatous subtype had a less favorable outcome compared with other subtypes ; in roux et al . study ( 6 ) , histological subtype did not seem to have any influence on the postoperative outcome . ( 6 ) , klekamp and samii ( 5 ) , haegelen et al . ( 4 ) and sandalcioglu et al . ( 3 ) all revealed significantly higher incidence of meningioma in women as in our study that revealed a female to male ratio of 1.8 to 1 . in the study of roux et al . ( 6 ) , as in our study sex had no influence on the prognosis . the average age of patients varies between 56 and 66 in studies of roux et al . ( 6 ) and haegelen et al . ( 4 ) respectively ; in our study the average age was 51.6 and prognosis was not influenced by increasing age . in schaller study age less than 60 years was correlated with a good outcome ( 11 ) . in sandalcioglu study ( 3 ) elderly patients proved to harbor an increased risk for surgical morbidity . in our study the patients age had no influence on the post - operative outcome . cervical location of the tumor was related with poor outcome in our study ; in schaller study ( 11 ) , tumor location below c4 seemed to be correlated with a good outcome ; in other studies ( 3 , 6 , 10 , 12 ) no correlation was found . incomplete removal of the tumor was seen in about half of the cases with poor outcome and 7% of the other group . since 80% of the incompletely removed tumors of the first group are of psammomatous subtype , it seems that incomplete removal of the tumor may be the reason of poor outcome in psammomatous subtype in comparison with other subtypes of who grade i , although further studies with larger sample size are needed to confirm this result . spinal meningioma of who grade i with psammomatous subtype are associated with less favorable postoperative neurologic outcome than other subtypes , with results closer to cases of who grade ii . incomplete resection of spinal meningioma occurs more frequently in psammomatous subtype and cases of who grade ii and trying to complete resection may cause additional neurological damage . cervical location is another factor that seems to have a negative correlation with a good outcome .