Anaplastic Oligodendroglioma with Transdural Extension

Oligodendrogliomas, the third most common primary gliomas, have a strict molecular definition, characterized by the combined presence of isocitrate dehydrogenase mutation and 1p19q codeletion. Herein, we describe an extremely unusual case of molecularly defined anaplastic oligodendroglioma with transdural extension into the frontal and ethmoid sinuses, without prior neurosurgical intervention or radiotherapy. The molecular profile of the tumor is also provided. To the best of our knowledge, this has never been reported before. Most of the previously reported glial tumors with transdural extension were cases of histologically proven glioblastomas and gliosarcomas, typically seen in the context of prior neurosurgical intervention and/or radiotherapy. This case adds to the limited literature on oligodendrogliomas with transdural extension. Further studies are necessary to elucidate the relationship between the incidence of transdural extension and molecular subtypes of oligodendrogliomas.