Challenging diagnosis: oligodendroglioma versus extraventricular neurocytoma

Mut M., Guler-Tezel G., Lopes M., Bilginer B., Ziyal I. , Ozcan O.

CLINICAL NEUROPATHOLOGY, vol.24, no.5, pp.225-229, 2005 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 24 Issue: 5
  • Publication Date: 2005
  • Page Numbers: pp.225-229
  • Keywords: oligodendroglioma, extraventricular, neurocytoma, FISH, anaplastic, LOW-GRADE GLIOMA, PROGNOSTIC-FACTORS, CHEMOTHERAPY, RADIATION, FEATURES, TUMORS


Diagnosis of oligodendroglioma from other clear cell neoplasms of central nervous system (CNS) is still challenging despite advances in neuroradiology and molecular diagnostic tools. Herein, we present a 44-year-old male patient who had a diagnosis of right parietal oligodendroglioma grade 11 in 1994 which recurred in 2002. He presented with intratumoral hemorrhage and he underwent radical resection of tumor in 2003. Histopathological examination of the recurrent tumor showed anaplastic progression with confusing immunohistochemical (IHC) results; the tumor was positive for NeuN and synaptophysin staining. The question arisen was whether the recurrent tumor was an oligodendroglioma with neuronal differentiation or an extraventricular neurocytoma initially misdiagnosed as oligodendroglioma. Repeated IHC staining showed negative results for NeuN and synaptophysin. Chromosomal analysis revealed 1p/19q deletion, which led to the diagnosis of anaplastic oligodendroglioma grade III. Accurate diagnosis of oligodendroglioma is crucial due to recent advances and promises in its treatment. Current diagnostic methods of oligodendroglial tumors are discussed in context of differentiating oligodendrogliomas from other clear cell neoplasms of CNS, especially from extraventricular neurocytomas.