title: An unusual meningioma variant with glial fibrillary acidic protein expression.
abstract: We studied a recurrent meningioma located in the right frontal lobe. The tumor showed high cellularity and the cells had plump, hyalinous cytoplasm. Immunohistochemically, almost all the tumor cells were positive for epithelial membrane antigen and vimentin, and unexpectedly, glial fibrillary acidic protein (GFAP). Ultrastructural investigation revealed abundant 8- to 10-nm filaments in the cytoplasm. Conspicuous interdigitations with numerous desmosomes were present. Frequently, intracellular and intercellular lumina lined by microvilli were also found. We considered the present case to be an unusual variant of meningioma with GFAP expression. A few cases of meningioma with triple expression of GFAP, vimentin and cytokeratin have been reported previously. However, the present case showed obvious pathological differences from these, and had no immunoreactivity for cytokeratin.
authors.affiliation: Department of Pathology, Niigata University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Su
authors.forename: K
authors.initials: K
authors.lastname: Ono
authors.forename: R
authors.initials: R
authors.lastname: Tanaka
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D005625:Frontal Lobe / Q000473:pathology; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D008579:Meningioma / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D012008:Recurrence; D014746:Vimentin / Q000378:metabolism
chemical_list: D005904:Glial Fibrillary Acidic Protein; D014746:Vimentin; D007633:Keratins