Sclerosing Meningioma: clinicopathological analysis of three cases

Sclerosing meningioma is a rare variant of meningioma. This tumor is characterized by a dense collagenous stroma with non‐calcified fibrous whorls and the presence of only scattered meningothelial cells. The diagnosis can be challenging due to paucity of tumor cells present. The clinical presentation, histologic findings, immunohistochemical and EM results of three cases are reported. METHODS Case 1: 21‐year‐old woman with a 1.4 cm left fronto‐temporal dural‐based mass. Case 2: 59‐year‐old man with a 2.5 cm left fronto‐parietal dural‐based mass. Case 3: 28‐year‐old man, status‐post whole brain radiation and chemotherapy for PCNS Lymphoma 14 years prior, with a 2.5 cm right frontal mass. Hematoxylin‐Eosin, Trichrome and immunohistochemical stains for EMA, Vimentin, GFAP, S100, CK, CD31 and Mib‐1 were performed. EM was done from paraffin embedded tissue. RESULTS: Complete excision was achieved in al cases. There was no evidence of tumor recurrence at four years, one year, and four months, respectively. All tumors showed dense collagen deposition with non‐calcified, dense collagen whorls, sometimes centered by a small vessel. Calcifications were absent or present only in the form of sparse psammoma bodies. The density of tumor cells ranged from practically acellular areas to scattered, small islands of meningothelial or spindle cells. EMA, Vimentin and S100 were positive in tumor cells. Mib‐1 stains showed low proliferation indices. The remaining immunohistochemical stains were negative. CONCLUSIONS: Recognition of this rare histologic variant of meningioma is important. The presence of sclerosing whorls appears useful to support the diagnosis. The paucity of tumor cells may render the diagnosis of meningioma difficult, and multiple sections and immunohistochemistry might be needed to support such diagnosis.