PMC9699836_01
Preoperative magnetic resonance imaging (MRI). T1 contrast-enhanced midsagittal MRI displays a tumor mass located in the pineal region, demonstrating heterogeneous post contrast opacification, signs of hemorrhage, and cystic areas (a and b). T2-weighted axial MRI reveals tumor hypercellularity, a ballooned third ventricle and enlarged lateral ventricles-signs of hydrocephalus (c).
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F1
Diffusion restriction and T2-hyperintense signal indicated tumor hypercellularity [Figure 1].
Hematoxylin and eosin-stained sections of paraffin embedded tissue show tumor tissue composed of papillary formations and cellular tumor with ependymal-like differentiation. Eosinophilic columnar or elongated cells are present in papillary areas around the vessels, while in ependymal-like areas gliovascular rosettes and tubes are noticed. The nuclei of tumor cells are round to oval, while atypical nuclei are only occasionally present. Microvascular proliferation is not present. Large foci of necrosis are without pseudopalisades of the surrounding tumor cells. Tumor tissue is diffusely immunopositive for AE1/AE3, sporadically positive for synaptophysin neuron-specific enolase, negative for chromogranin, Neu-N, and Epithelial membrane antigen. Nuclear INI1 expression is present in tumor cells. Mitotic activity ranges from 4 to 10 per 10 HPF, while Ki67 values range from 2% to 8%. Tumor showed complete absence of immunoreactivity for glial fibrillary acidic protein.
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F2
Therefore, histological diagnosis of the tumor was PTPR [Figure 2].
Postoperative magnetic resonance imaging (MRI). T1-weighted mid-sagittal (a) and T2-weighted axial (b) MRI scans show no signs of residual/recurrent tumor mass or hydrocephalus.
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F3
Postoperative MRI of brain and total spinal cord found no residual tumor or signs of leptomeningeal dissemination [Figure 3].