rPNET is characterized by small uniform round cells with focal Homer-Wright rosettes or perivascular seudo-rosettes formation.
B) In some areas, characteristic Homer-Wright rosettes could be seen (H&E, x200).
Common features of ENB on light microscopy include small, round-to-oval cells with coarsely granular chromatin, multiple small nucleoli, prominent nuclear membranes, and scant cytoplasm with pseudo rosette or occasional Homer-Wright rosettes
separated by fibrous septa.
10) A PNET has morphologic evidence of neural differentiation, which is demonstrated histologically by Homer-Wright rosettes
, immunohistochemically by expression of at least 2 neural markers, or ultrastructurally by the presence of neural elements.
13] The histologic hallmark of PNET is formation of Homer-Wright rosettes
or pseudorosettes involving hyperchromatic cells.
The neoplastic growth is composed of sheets of undifferentiated small blue cells with occasional Homer-Wright rosettes