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57th Annual Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN)

German Society for Neuropathology and Neuroanatomy

12. - 15.09.2012, Erlangen

57th Annual Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN)

Spinal pilomyxoid astrocytoma developing a LOH 1p19q and cerebral metastasis

Meeting Abstract

  • presenting/speaker Sabina Eigenbrod - Ludwig-Maximilians-University, Neuropathology, Munich, Germany
  • Niklas Thon - Ludwig-Maximilians-University, Neurosurgery, Munich, Germany
  • Nathalie Jansen - Ludwig-Maximilians-University, Nuclear Medicine, Munich, Germany
  • Hendrik Janssen - Ludwig-Maximilians-University, Clinical Radiology, Munich, Germany
  • Janina Mielke - Ludwig-Maximilians-University, Neuropathology, Munich, Germany
  • Michael Ruiter - Ludwig-Maximilians-University, Neuropathology, Munich, Germany
  • Christian la Fougère - Ludwig-Maximilians-University, Nuclear Medicine, Munich, Germany
  • Aurelia Peraud - Ludwig-Maximilians-University, Neurosurgery, Munich, Germany
  • Rupert Egensperger - Ludwig-Maximilians-University, Neuropathology, Munich, Germany
  • Hans Kretzschmar - Ludwig-Maximilians-University, Neuropathology, Munich, Germany

Deutsche Gesellschaft für Neuropathologie und Neuroanatomie. 57th Annual Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN). Erlangen, 12.-15.09.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. Doc12dgnnPP3.22

DOI: 10.3205/12dgnn066, URN: urn:nbn:de:0183-12dgnn0665

Published: September 11, 2012

© 2012 Eigenbrod et al.
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Outline

Text

Background: Spinal glioma are rare and their biological behavior can differ from their cerebral counterparts. Pilomyxoid astrocytoma (PMA, WHO °II) typically occur in the hypothalamic/chiasmatic region of children. The few reported cases of pediatric spinal PMA displayed a particularly aggressive behavior (Paraskevopoulos D et al. 2011).

Case report: We report a 5 year old female patient presenting with a spinal glioma in 1999 and local tumor recurrence in 2002. In 2011, MRI demonstrated a second tumor intracerebrally and further progression of the spinal tumor.

Methods: We performed a comprehensive histological and molecular analysis of the tumors from both localizations.

Results: Histological examination of the 1999 spinal tumor revealed a PMA, WHO °II. The local recurrence in 2002 showed features of a pilocytic astrocytoma, compatible with a maturation process (Johnson MW et al. 2011). However, there was a high proliferation rate (Ki67 ~20%). In both samples, molecular analysis showed: MGMT: not methylated, IDH1/2 and BRAF: no mutation, 1p19q: no LOH. In contrast, the histological picture of the cerebral tumor manifestation showed features of an anaplastic oligodendroglioma. Interestingly, genetic analysis revealed a 1p19q codeletion, all other markers were identical to the spinal tumor. Of note, surgical specimen from the progressive spinal tumor obtained in 2012 showed both pilomyxoid and oligodendroglioma-like areas. The latter were selected for genetic analysis and also showed a 1p19q codeletion.

Discussion: These findings indicate that the spinal PMA first developed a 1p19q codeletion resulting in an oligodendroglioma-like phenotype and then resulted in a cerebral metastasis. The simultaneous existence of 2 distinct tumors appears extremely unlikely, also because virtually all 1p19q co-deleted oligodendroglial tumors also harbor IDH1/2 mutations and a methylated MGMT promoter sequence.

Conclusion: This unusual case suggests that PMA comprise a heterogeneous group possibly including aggressive subtypes, not compatible with the current classification according to WHO °II. In addition, the case emphasizes the increasing relevance of genetic markers complementing classic histological diagnosis.