PMC3205501_01
(a) Plain computed tomography (CT) of the head revealing a 40-mm-diameter tumor with calcification and cyst formation in the right parietal lobe. (b, c) Axial images are shown for magnetic resonance imaging (MRI). T2 and T2*-weighted imaging shows signal hyperintensity. T2 and T2*-weighted imaging reveals an area of marked hypointensity around the solid component, which may represent the calcification seen on CT or hemosiderin deposition due to an old hemorrhage. (d-f) Coronal images are shown for MRI. T1 gadolinium enhancement shows a heterogeneous contrast effect. Note: The normal-appearing choroid plexus was placed within the lateral ventricle and continuity of the normal choroid plexus and the lesion was not confirmed
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F1
Normal choroid plexus of the right lateral ventricle was located in the normal position, and continuity of the normal choroid plexus to the tumor was not confirmed [Figure 1].
(a) Intraoperative microscopic view. The yellowish, granulomatous, slightly hard tumor was located in the right parietal lobe. (b) The tumor was firmly adhered to the cerebral ventricular wall, and the lateral ventricle was opened during resection of the deepest part of the tumor. Arrow ( ) indicates the tumor margin. Asterisk (*) indicates the opening in the lateral ventricle
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F2
The lateral wall on the lateral ventricle showed a normal appearance and continuous coverage with ependymal [Figure 2].
(a) The tumor tissue consists mainly of a fibrous component with crystal and hemosiderin deposition and macrophages. Densely proliferating cells with ovoid nuclei and resembling choroid plexus epithelium are observed in the peripheral area, showing a papillary architecture. (b) Vimentin was strongly immunoreactive. (c) N-CAM (CD56) exhibited focal immunoreactivity. (d) EMA exhibited focal immunoreactivity. (e) CK7 exhibited focal immunoreactivity. (f) GFAP was strongly immunoreactive. (g) Podoplanin exhibited focal immunoreactivity, contained a few reactive cells, if any. (h) In addition, activated macrophages were prominent around the cerebral parenchyma and were considered to represent a reactive lesion in relation to an old hemorrhage. (i) Papillary architecture was observed, extending further into the cerebral parenchyma (x100 for a-c, h, i; x200 for d-g)
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F3
Protein (GFAP) was strongly immunoreactive. Podoplanin exhibited focal immunoreactivity in a few reactive cells [Figure 3].