id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
fnp-3276	Perry, Arie	The definition and role of brain invasion in meningioma grading: Still controversial after all these years	2021		.htm	application/xhtml+xml	2778	146	46	505 Parnassus Avenue, M551, Box 0102 · San Francisco, CA 94143 · USA Arie.Perry@ucsf.edu Submitted: 05 March 2021 Accepted: 23 March 2021 Copyedited by: Nima Sharifai Published: 24 March 2021 https://doi.org/10.17879/freeneuropathology-2021-3276 Keywords: Meningioma, Brain invasion, Grading In their landmark 1938 monograph on meningiomas, Cushing and Eisenhardt stated that brain invasion, defined similarly to today by tumoral penetration of the pia, had long been considered a sign of malignancy1. As such, this question remains unanswered and the upcoming 5th edition of the WHO (in press) will include the following text on the question of brain invasion: “Brain invasion by meningioma is characterized by irregular, tongue-like protrusions of tumour cells into underlying GFAP-positive parenchyma, without intervening leptomeninges.	cache/fnp-3276.htm	txt/fnp-3276.txt