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Int J Clin Exp Pathol 2012;5(3):231-242

Original Article
The histopathological spectrum of human meningiomas

Thomas Backer-Grøndahl, Bjørnar H Moen, Sverre H Torp

Department of Laboratory Medicine, Children’s and Women’s Health, University Hospital, NTNU, Trondheim, Norway; Department of Pathology
and Medical Genetics, St. Olavs Hospital, Norway

Received March 2, 2012; accepted March 15, 2012; Epub March 25, 2012; Published March 30, 2012

Abstract: Histopathological examination and grading of meningiomas gives valuable prognostic information, although the method is subject
for interobserver variability. The aim of this study was to review a large series of human meningiomas in order to examine the frequency of
benign (grade I), atypical (grade II), and anaplastic (grade III) forms depending on various WHO classification schemes. In addition, we wanted
to describe the frequency of various histopathological features and their mutual correlations. Sections from 196 consecutively treated primary
human meningioma patients were revised retrospectively. The established criteria to grade meningiomas, which are also known to be
associated with tumorigenesis, were shown to correlate significantly. The number of grade II meningiomas increased when using the WHO
2007 classification (30%) compared with previous editions, mainly due to the definition of brain infiltrating meningiomas as atypical (grade II). A
bimodal frequency distribution among age groups of females was observed. Continuous revision of histopathological classification systems is
required to improve the diagnostic accuracy. (IJCEP1203001

Keywords: Brain tumors, diagnosis, grading, classification, Clemmesen’s hook

Address all correspondence to:
Dr. Sverre H Torp
Department of Pathology and Medical Genetics
St. Olavs Hospital, Trondheim University Hospital
Laboratory Center, Erling Skjalgssonsgate 1
7006 Trondheim, Norway.
Tel: (+47) 72 57 33 65; Fax: (+47) 72 57 64 28
E-mail: sverre.torp@ntnu.no