Nestin expression in central nervous system germ cell tumors

Central nervous system (CNS) germ cell tumors constitute a unique class of rare tumors that mainly affect children and adolescents. These tumors are believed to originate from displaced primordial germ cells. Recently, results of treatment of germ cell tumors have improved with use of radiotherapy and combination chemotherapy. However, some tumors have proven refractory to intensive treatment with surgery, radiation, and combination chemotherapy. Nestin is an intermediate filament protein expressed in undifferentiated cells during CNS development and in CNS tumors and is used as a marker of immature elements of tumors, including brain tumor stem cells. In this study, we examined for the first time nestin expression in 19 CNS germ cell tumors (nine pure germinomas, five germinomas with syncytiotrophoblastic giant cells, one yolk sac tumor, one choriocarcinoma, one embryonal carcinoma, and two mature teratomas). Nestin was expressed in 14 cases but was not expressed in three pure germinomas and two mature teratomas. Clinically, nestin-negative tumors did not exhibit dissemination, while all tumors that exhibited dissemination also strongly expressed nestin protein. These findings suggest that the detection of nestin expression could be useful in the management of CNS germ cell tumors, as an auxiliary predictor of dissemination and/or progression.