Recurrent KBTBD4 small in-frame insertions and absence of DROSHA deletion or DICER1 mutation differentiate pineal parenchymal tumor of intermediate differentiation (PPTID) from pineoblastoma
The pineal body is a small endocrine gland in the midline of the brain that secretes melatonin to modulate circadian rhythms. A group of primary tumors which arise from the pineal gland termed pineal parenchymal tumors are classified as pineocytoma (grade I), pineal parenchymal tumor of intermediate differentiation (PPTID; grade II or III), or pineoblastoma (grade IV). Most pineoblastomas arise in children, whereas pineocytomas and PPTIDs typically occur later in life. Pineocytomas are associated with favorable prognosis, with 5-year survival exceeding 90% following gross total resection. In contrast, pineoblastomas are embryonal tumors with a propensity for cerebrospinal dissemination and poor outcome despite resection, craniospinal radiation, and systemic chemotherapy . PPTIDs are morphologically heterogeneous with intermediate histologic features and variable clinical outcomes [3, 5]. Recently, pineoblastomas were identified to harbor frequent mutations of the DICER1gene or...
This study was supported by the NIH Director’s Early Independence Award (DP5 OD021403) and a Career Development Award from the UCSF Brain Tumor SPORE grant (NIH P50 CA097257) to D.A.S. We thank the UCSF Brain Tumor Tissue Bank (supported by NIH P50 CA097257) for supplying key samples.
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Conflict of interest
The authors declare that they have no competing interests related to this study.
This study was approved by the Committee on Human Research of the University of California, San Francisco, with a waiver of patient consent.