XXXX . A histological and immunohistochemical study.

@entity1 @entity5 @entity538 @entity730 @entity3508 @entity2946
The histological and immunohistological features of @entity2946 were investigated in @entity1 participating in an ongoing cooperative study of the Societ   International d'Oncologie P  diatrique (SIOP). Of 51 @entity5 , four were the classic desmoplastic variant. In regard to the histological features used to grade @entity5 , considerable inter- and intratumoral variation was observed. The @entity5 with the most pleomorphic and coarsely structured nuclei tended to be neuroblastic, whereas the most delicate and uniform nuclei were found in the @entity5 . Twenty-one of the cases exhibited neuroblastic differentiation in the form of neuroblastic rosettes. Of these, three also contained neoplastic ganglion cells. Of the five @entity2946 that were calcified, four contained neuroblastic rosettes in accord with the tendency for @entity730 . In many of the @entity5 , islands of markedly @entity3508 ( @entity3508 )-positive cells were seen. Although the limited specificity of this marker enzyme is recognized, we believe that this focal intense staining could indicate neuronal differentiation somewhat more advanced than in small @entity3508 -positive islands of reduced cellularity, many of which were strongly positive. The nuclei in these island were usually larger and more vesicular than those in the surrounding densely cellular areas. These features and the frequent association with Homer-Wright rosettes suggest that these foci represent a form of neuronal differentiation. Astrocytic differentiation was more difficult to define and required the use of staining for @entity538 ( @entity538 ). Six @entity5 contained @entity538 -positive cells that were clearly neoplastic. Many others contained scattered reactive astrocytes and dispersed cells whose neoplastic versus reactive nature could not be defined.(ABSTRACT TRUNCATED AT 250 WORDS)
