Brain Pathology Case of the Month - May 2010

Contributed by Eytan Raz 1, Manila Antonelli 2, Angelo Pichierri 1, Arturo Consoli1, Felice Giangaspero 2, Marco Fiorelli 1
    1. Department of Neurological Sciences - Sapienza University of Rome - Italy
    2. Department of Pathology - Sapienza University of Rome - Italy


The patient is a previously healthy 35-year-old man who was admitted to our hospital for evaluation after experiencing vomitus, dizziness and headache for one month. A neurological examination elicited no abnormalities. CT and MR imaging were performed and revealed a 3.5 x 3.2 cm solitary, well-delineated, extra-axial midline mass arising from the frontal falx cerebri. The lesion was isointense to the cortex on T2 (Figure 1) and hypointense on T1, with a marked homogenous enhancement after intravenous contrast administration (Figures 2 and 3). Based on these findings, the radiological diagnosis was meningioma of the falx. At surgery, the tumour appeared as an extra-axial lesion and was removed via a left midline frontal craniotomy. The excision was macroscopically complete.


Macroscopically, the surgical specimen was whitish, soft, well circumscribed and measured 1.6 cm in diameter. Intraoperative pathological examination is not routinely performed during removal of meningiomas.


Microscopic features showed a neoplasm with high cellularity. The cells had irregular nuclei, the majority of which were naked, and in their midst were gemistocytic cells as well as pleomorphic cells with vescicular nuclei and abundant, eosinophilic cytoplasm. (Figure 4). Mitotic figures were seen (3/10HPF), but without necrosis or microvascular proliferation. These cells laid in a fibrillary background. On immunohistochimical examination, the neoplasm was reactive for glial fibrillary acidic protein (GFAP - Figure 5); MIB-1 index was about 15% (Figure 6). P53 protein was overexpressed (Figure 7).


International Society of Neuropathology