I.17 Meningioma

PI17a2 - Click here to make me bigger
PI.17.a2 Meningioma (frontal section). Tumor adhering to the falx cerebri, displacing the median aspect of the frontal lobe. Meningioma can develop anywhere there are arachnoid cells, even in the axis of the choroid plexuses. Multiple meningiomas can occur. The numerous histologic subtypes of meningioma all exhibit positive immunoreactivity for VIM and EMA. In addition to "CLASSICAL" subtypes (meningothelial, fibrous, transitional, psammomatous, angiomatous meningioma), other meningiomas have been more recently classified according to their particular CELL CONTENTS (secretory, xanthomatous, lipomatous, clear cell meningioma) or the presence of abundant STROMA (microcystic, chordoid, lymphoplasmacyte-rich meningioma). Mixed tumours may exhibit the characteristics of two or more subtypes.