Survivin expression in ganglioglioma.

Gangliogliomas are unusual central nervous system (CNS) neoplasms occurring mainly in children and young adults and inducing chronic pharmacoresistant epilepsy. These are usually well differentiated neuroepithelial tumors composed of neurons in association with neoplastic glial cells. Gangliogliomas present with favorable outcome. However, some may recur and/or progress to anaplasia and be associated with a dismal prognosis. Since histopathological features do not consistently correlate with clinical outcome, reliable prognostic factors have yet to be defined in gangliogliomas. Survivin is an anti-apoptotic protein whose expression has been found to be of prognostic significance in many human cancers, including gliomas. The objective of this study was to assess survivin expression using immunohistochemistry in 15 gangliogliomas. Ten lesions were low-grade neoplasms whereas 5 were high-grade tumors. Survivin expression appeared restricted to the neoplastic glial component and was detected in 6/15 gangliogliomas. Two additional tumors expressed survivin upon relapse. Half survivin expressing lesions displayed less than 1% immunoreactive cells. Survivin expression in more than 5% neoplastic glial cells was detected only in malignant and/or recurrent gangliogliomas. Extended lifespan in survivin expressing cells might enhance aggressive behavior in these tumors through accumulation of mutations, thereby allowing progression to malignant phenotypes. Survivin expression may carry a negative prognostic value in gangliogliomas.