[Diagnostic use of D2-40 and annexin-1 in ependymal tumors]

To investigate the diagnostic significance of D2-40 and annexin-1 in the ependymal tumors.

To analyses the expression of D2-40, annexin-1, EMA and Ki-67 by immunohistochemistry in 52 cases of ependymal tumors (48 cases of ependymomas, 4 cases of choroid plexus papilloma) from Xuanwu Hospital from 2005 to 2009. Ten cases of corresponding normal brain tissue were also obtained as control.

Thirty-two of forty-eight (66.7%) cases of ependymomas were positive for D2-40. "Dot-like" and "ring-like" structures were commonly observed in ependymomas (55.3%, 21 of 38 cases) and anaplastic ependymomas (5 of 6 cases) with D2-40 staining. There was no difference in the expression between D2-40 and Ki-67 (r(s) = -0.013, P = 0.931). For annexin-1, 87.5% (42 of 48 cases) of the ependymomas were positive. The specific "granular structures" and cilium were observed in ependymomas (1 of 4 cases of myxopapillary ependymomas and 11 of 38 cases of ependymomas respectively) for annexin-1. The difference in expression between annexin-1 and Ki-67 was statistically significant (r(s) = -0.405, P = 0.005). D2-40 in combination of EMA and annexin-1 increased the positive rate to 100% in ependymomas. Choroid plexus papillomas were all positive for D2-40 and annexin-1. The control tissue was negative for D2-40 but positive for annexin-1 in the capillaries.

The specific structures are valuable in diagnosing of ependymal-genetic tumors, and are highlighted by D2-40 and annexin-1. D2-40 in combination of EMA and annexin-1 is a useful diagnostic marker for ependymal tumors.