Adult supratentorial extra-pineal primitive neuro-ectodermal tumors.

Primitive neuro-ectodermal tumors (PNET) are rare malignant brain tumors, mostly undifferentiated, that tend to spread through the cerebrospinal fluid (CSF). Extra-pineal supratentorial PNET in adults are very rare. Published guidelines for adult PNET were not available until 2011, and at our institute surgeons and oncologists did not have consensus on imaging evaluation or treatment protocols between 1994 to 2008. Twenty-two consecutive adult patients with extra-pineal supratentorial PNET from this period were reviewed in this retrospective study. Their clinical profiles and radiologic images were evaluated. A pathological review based on the 2007 World Health Organization criteria was also conducted. Prognostic factors were analyzed. The 1 and 3 year overall survival rates were 64% and 32% for adult extra-pineal supratentorial PNET, respectively. Limited by the small number of tumors in this series, we suggest that negative prognostic factors are multiplicity at onset, initial CSF seeding, and tumor differentiation. Although age of onset, extent of resection, radiation and chemotherapy were assumed to be good prognostic factors, the analysis did not reveal strong significance for overall survival with univariate and multivariate analysis. We believe more detailed investigations on the genetic/molecular basis of supratentorial PNET and their clinical outcomes are warranted.