Is Anaplastic Oligodendroglioma Prone to Extracranial Metastasis? A Case Report and Review of Literature

Background: It is generally accepted that gliomas rarely metastasize outside the central nervous system (CNS). However, the issue that anaplastic oligodendrogliomas is prone to spread outside CNS is being disputed again. Methods: We described in detail the clinical case of one patient with recurrent anaplastic oligodendroglioma, which metastasized to right pelvis bones 5 years after second neurosurgical procedures. Genetic analyses included detection of 1p and 19q loss of heterozygosity (LOH) and IDH-1 mutations. A review of literature was conducted on metastatic anaplastic oligodendrogliomas. Results: A puncture biopsy of the right ischium bone in this patient revealed that high grade glioma cells had infiltrated the right ischium marrow. Moreover, the diagnosis of multiple-bone metastases of glioma was confirmed by the whole-body [18F] fluorodeoxyglucose positron emission tomography computed tomography (PET/CT) scan. Immunohistochemisty stain analyses showed that the right ischium metastasis glioma cells originated from right parietal lobe anaplastic oligodendrogliomas. The 1p and 19q LOH and the R132H site mutation of IDH-1 were detected in the samples of the recurrence brain tumor in 2009. Conclusions: The incidence of extracranial metastases in anaplastic oligodendrogliomas is very low but they do occur; bone metastasis may be the most common site. The molecular markers such as the 1p/19q LOH and IDH-1 mutations not only help prove the pathologic diagnosis of oligodendrogliomas, but also help elucidate a subtype of anaplastic oligodendrogliomas which has a good prognosis even with extracranial metastases.