Durable response to mTOR inhibition in a patient with relapsing papillary tumor of the pineal region

Papillary tumor of the pineal region (PTPR) was first described as a distinct tumor entity by Jouvet et al in 2003¹ and was eventually included in the 2007 World Health Organization (WHO) classification of CNS tumors as a rare neuroepithelial tumor characterized by papillary architecture and epithelial cytology.² PTPR mostly occurs in younger adults and shows frequent local recurrence after surgery, which corresponds to WHO grade II or III.² So far, there is no established oncological treatment of these patients. We previously described that loss of chromosome 10 and phosphatase and tensin homolog (PTEN), and associated pathological activation of the Akt/mammalian target of rapamycin (mTOR) pathway, is a hallmark of PTPR.³ Here, we for the first time report a patient case with relapsing and rapidly progressing PTPR that showed loss of chromosome 10 and PTEN, phosphatidylinositol-3 kinase (PI3K)/Akt/mTOR hyperactivity, and a dramatic and durable response to mTOR inhibition with everolimus.