Dual use of E-cadherin and D2-40 immunostaining in unusual meningioma subtypes.

Abstract

Meningiomas usually can be readily diagnosed on H&E alone, although occasionally immunohistochemistry (IHC) confirmation is desirable. Studies exploring the diagnostic utility of either podoplanin (D2-40) or E-cadherin IHC in meningiomas have conflicted, and no studies exist in which the two IHCs have been used in combination for diagnosis. E-cadherin and D2-40 IHC was performed on 77 meningiomas (31 ordinary; eight microcystic; four rare myxoid; six metaplastic; six invasive of orbit, muscle, and/or soft tissue; two metastatic; six brain-invasive World Health Organization [WHO] grade II, nine non-brain-invasive WHO grade II; and five anaplastic WHO grade III), with semi-quantitative scoring on a three-tier scale (0, focal [1+], strong/diffuse [2+]). All meningiomas were either E-cadherin or D2-40 IHC+, with 69 of 77 showing dual immunostaining, most at the 2+ level. No downregulation of E-cadherin IHC was found in invasive or high-grade meningiomas. Dual E-cadherin/D2-40 IHC can supplement diagnosis of meningioma.