title: Primitive neuroectodermal tumor with choroid plexus differentiation.
abstract: A case of a cerebral juvenile undifferentiated round cell tumor with unusual formation of glandular structures is presented. The round cell component showed focal expression of glial fibrillary acidic protein, S-100 protein, neurofilament protein and neuron-specific enolase. The glandular part consisted of papillary epithelial structures with a central PAS-positive lumen. Ultrastructural findings supported the interpretation of these parts as choroid plexus. This route of differentiation was recognizable at the first operation at the age of 5 years and was much more prominent in the recurrence found 7 1/2 years later. The unusually benign course of this primitive neuroectodermal tumor (PNET) may be due to its intrinsic progressive tendency towards choroid plexus differentiation.
authors.forename: R C
authors.initials: RC
authors.lastname: Janzer
authors.forename: P
authors.initials: P
authors.lastname: Kleihues
mesh_terms: D001706:Biopsy; D001932:Brain Neoplasms / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D002648:Child; D002675:Child, Preschool; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D009364:Neoplasm Recurrence, Local; D009373:Neoplasms, Germ Cell and Embryonal / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D009778:Occipital Lobe; D013702:Temporal Lobe