“…It is important to underline that pineal papillary tumors present wide morphological variability [ 82 , 92 , 93 , 94 , 95 ]. Apart from the characteristic papillary structures, papillary tumors have morphological features in common with other papillary-like tumors that occur in the pineal region, including pineal parenchymal neoplasms, choroid plexus papillomas, papillary ependymomas, metastatic papillary carcinomas, papillary meningiomas, and germ cell tumors, which complicates the clinical diagnosis [ 60 , 83 , 87 , 92 , 96 , 97 ]. These pineal tumors often present increased proliferative activity (Ki67/MIB1 proliferation index) [ 90 ], which is correlated with worse prognosis.…”