History of Management of Supratentorial Primitive Neuroectodermal Tumors in Children
Understanding of Disease
1973 – considered similar to medulloblastoma: These tumors were first described in 1973 by Hart and Earle, who described PNETs as tumors that were morphologically similar to medulloblastomas but occurred outside the cerebellum.
1993 – unifying theory: In 1993 the W.H.O. recommended classifying medulloblastomas and PNETs under a single category, namely PNET. Those PNETs occurring in the cerebrum or suprasellar region are referred to as supratentorial PNETs. Pineal PNETs, otherwise known as pineoblastomas, are not considered by the W.H.O. to be supratentorial PNETs and have been excluded from discussion in this chapter.
Subsequent recognition of differences: Within the group of supratentorial PNETs, tumors with a clear neuronal component have been subclassified as cerebral neuroblastomas, and those containing ganglion cells as ganglioneuroblastomas. All PNETs are considered W.H.O. tumor grade IV. Despite the histopathological similarities between supratentorial PNETs and infratentorial PNETs (medulloblastomas), these tumors exhibit different molecular genetics and important differences in terms of response to therapy and outcome. As such, supratentorial PNETs must be considered as distinct from medulloblastomas (see Table).
Diagnostic neuroradiology: As for other supratentorial tumors, advances in neuroradiology have improved the diagnosis of supratentorial PNETs.
Imaging and imaged-guided surgery: Advances in neuroradiology, mainly MRI, coupled with neuronavigation have improved the ability to resect supratentorial PNETs more safely.