PMC5820897_01
Computed tomography scan (axial with or without contrast): A large midline posterior fossa lesion occupying the fourth ventricle with evidence of calcification in the periphery
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F1
Computerized topography of the brain showed a large posterior fossa nonenhancing fourth ventricular lesion containing hemorrhage and calcification and causing obstructive hydrocephalus [Figure 1].
Magnetic resonance imaging scan (T2-weighted axial (a) and sagittal (b)): Midline posterior fossa cystic tumor lesion occupying the fourth ventricle and extending down to C1 and pushing the brainstem anteriorly. The lesion has two components: Anterior and posterior
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F2
Magnetic resonance imaging (MRI) of the brain showed a midline posterior fossa cystic lesion measuring 7.2 cm in the craniocaudal plane and 5.5 cm x 4.1 cm in the axial plane [Figure 2a and b].
Histopathological specimen (H and E stain): A cyst wall lined by flat, simple to stratified squamous with peripheral palisaded cells, fibrosis and chronic inflammation (a). The attenuated central keratinizing epithelium is giving rise to squamoid cell ghosts referred to as "wet keratin" (b). The cyst wall shows cholesterol clefts and ossification/calcification (c)
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F3
These features were diagnostic of adamantinomatous type craniopharyngioma [Figure 3a-c].