Brain Pathology Case of the Month - June 2003

Contributed by Iezza G1, Loh C2, Lanman TH3, Yong WH1
  1Departments of Pathology and Laboratory Medicine (Neuropathology), 2Radiology (Neuroradiology), and 3Surgery (Neurosurgery), Cedars-Sinai Medical Center and UCLA School of Medicine, Los Angeles, CA 90048
Published on line in June 2003


A 33 year old male with a long history of epilepsy was evaluated for a seizure. A general neurologic examination was unremarkable. Radiologic studies of the brain revealed a right frontal mass. Multiplanar, multisequential magnetic resonance images of the brain with intravenous gadolinium showed a homogeneously enhancing subfrontal extra-axial mass measuring 3.5 x 2.3 x 2.0 cm located right to the midline with surrounding edema, minimal midline shift and mild deformity of the right frontal horn (Fig. 1A). The lesion was broad based with dural extension into the anterior falx. Sagittal images showed irregular margins at the brain interface suggesting an intra-axial component (Fig. 1B). At the time of surgery, the frontal cortex was noted to have a "rock" hard consistency. Both the cortical and extra-axial (dural) components were grossly completely excised.


Microscopically, the lesion consisted of two components. The extra-axial mass was composed of fascicles and whorls of predominantly fibrous meningothelial cells (Fig. 2) with focal psammoma bodies. A minor component demonstrated tight whorls (Fig. 3). The intra-axial component consisted of a distorted cerebral cortex, characterized by a vascular (Fig. 4) and meningothelial proliferation with psammoma bodies (Fig. 5). Dense intervening gliosis was highlighted by a GFAP immunostain (Fig. 6). Some of the entrapped neurons demonstrated tau immunopositive neurofibrillary tangles (Fig. 7). MIB-1 staining was less than 1% in the cortical and extra-axial tissue. EMA stained some of the cortical meningothelial whorls.


International Society of Neuropathology