PMC7232711_01
(a) Coronal T2 WI. (b, c) Axial T2 WI. (d, e) Axial T1 WI. (f, g) Axial DWI and ADC map. (h) Axial T1 postcontrast. (a-h) A large soft tissue mass is noted at the left cerebellopontine angle demonstrating an intermediate hyperintense signal on T2WI and hypointense signal on T1WI with mild restriction on DWI and faint homogenous enhancement after contrast. (a) The mass is causing hydrocephalus which has resolved with bilateral small subdural collections, related to the reduced intracranial pressure, following surgery.
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fig1
Investigations and radiological imaging in private hospitals identified a posterior fossa space-occupying lesion (Figure 1).
(a) A panoramic view of chondro-osseous ependymoma. (b) Very low magnification (20x) of the hematoxylin and eosin-stained section depicting chondro-osseous metaplasia within the substance of conventional ependymoma (areas of anaplasia are not shown). (c, d) At slightly higher magnification (200x and 400x), the organized hyaline cartilage formation and ossification is appreciated. (e) Another low-power field (20x) exhibiting the classic ependymal differentiation in the form of pseudorosettes. (f) Dot-like staining by EMA immunostain.
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fig2
The histopathological examination of the posterior fossa tumor showed mostly a moderately cellular glial tumor with perivascular pseudorosettes (Figure 2). EMA immunostain showed a perinuclear dot-like pattern (Figure 2(f)).