PMC4533491_01
A: CT scan revealing a low-density lesion. B: T1-weighted MRI showing a low-density lesion. C: T2-weighted MRI showing a high-density lesion. D: Tumor showing an enhanced wall on enhanced T1-weighted MRI. E: Early 201Tl SPECT image showing high tumor uptake. F: Delayed 201Tl SPECT image showing high tumor uptake. CT: computed tomography, MRI: magnetic resonance imaging, 201Tl SPECT: Thallium-201 single-photon emission computed tomography.
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F1
CT revealed a low-density lesion with edema (Fig. 1A), whereas angiography did not demonstrate any tumor staining (data not shown). The tumor appeared as a low-density lesion on T1-weighted magnetic resonance imaging (MRI) (Fig. 1B) and as a high-density lesion on T2-weighted MRI (Fig. 1C). On enchanced T1-weighted MRI, the tumor appeared to have an enhanced wall (Fig. 1D). Early phase 201Tl SPECT images showed high tumor uptake (Fig. 1E), which was particularly prominent in the delayed phase (Fig. 1F).
A, B: Histological examination, indicative of a microcystic meningioma, showing variable-sized tumor cells with vacuolated cytoplasm and elongated cell processes forming microcystic spaces (hematoxylin and eosin stain) (A x40, B x200). C: Vimentin positivity on immunostaining (x200), D: Epithelial membrane antigen positivity on immunostaining (x100). E: MIB-1 index ranged from 3% to 5% (x100). MIB-1: mindbomb homolog 1.
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F2
Histological examination revealed a tumor characterized by vacuolated cells with abundant cytoplasmic processes forming variable-sized microcysts (Fig. 2A, B). Immunohistochemically, the tumor cells were diffusely positive for vimentin (Fig. 2C) and focally positive for epithelial membrane antigen (Fig. 2D). The mindbomb homolog 1 (MIB-1) index, detected by Ki67 staining, ranged from 3% to 5% (Fig. 2E).