Glioneuronal phenotype in a diencephalic pilomyxoid astrocytoma.
We report the presence of divergent populations of cells in a hypothalamic/chiasmatic pilomyxoid astrocytoma of an 11-month-old male, exhibiting differential immunohistochemical localizations for glial fibrillary acidic protein (GFAP) and synaptophysin. The tumor cells were negative for Neu-N and neurofilament protein. Ultrastructurally, the tumor comprised 2 cell types, one with features attributable to a neuronal phenotype alongside cells exhibiting an overt astroglial phenotype. This composite organization was confirmed by confocal microscopy, which revealed 2 distinct, albeit tightly interwoven, populations of GFAP and synaptophysin-labeled tumor cells. Our results indicate that a subset of the so-called pilomyxoid astrocytomas of the hypothalamic/chiasmatic region may represent phenotypically mixed glioneuronal neoplasms distinct from the pilocytic astrocytomas.
de Chadarévian
Jean-Pierre
JP
Department of Pathology and Laboratory Medicine, Drexel University College of Medicine and St. Christopher's Hospital for Children, Erie Avenue at Front Street, Philadelphia, PA 19134, USA. JD37@Drexel.edu
Halligan
Gregory E
GE
Reddy
Goutham
G
Bertrand
Louise
L
Pascasio
Judy M
JM
Faerber
Eric N
EN
Katsetos
Christos D
CD
D001253:Astrocytes / Q000648:ultrastructure; D001254:Astrocytoma / Q000737:chemistry / Q000473:pathology*; D001932:Brain Neoplasms / Q000737:chemistry / Q000473:pathology*; D018303:Ganglioglioma / Q000737:chemistry / Q000473:pathology*; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006801:Humans; D007031:Hypothalamus / Q000473:pathology*; D007124:Immunoenzyme Techniques; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D009474:Neurons / Q000648:ultrastructure; D010641:Phenotype; D016708:Synaptophysin / Q000032:analysis
D005904:Glial Fibrillary Acidic Protein; D016708:Synaptophysin