[An unusual and misleading form of pilocytic astrocytoma]
Fanny Burel-Vandenbos1, Anne Jouvet, Stéphane Chanalet
1Laboratoire d'Anatomie Pathologique, Laboratoire d'Anatomie Pathologique, Hôpital Pasteur, 30 avenue de la voie romaine, 06000 Nice. burel-vandenbos.f@chu-nice.fr
Abstract:
Pilocytic astrocytoma is histologically characterized by a biphasic pattern. We report a myxoid form of frontocallosal pilocytic astrocytoma in a 13-year-old girl. MRI showed a relatively well-defined tumor with necrosis and ring-like zone of contrast enhancement. Histological examination showed a monophasic tumor composed of piloid cells on a myxoid background corresponding to a pilomyxoid astrocytoma. This unusual form of pilocytic astrocytoma can be mistaken for a high grade infiltrating glioma. Pilomyxoid astrocytoma is more aggressive than classic pilocytic astrocytoma and has to be distinguished from it.
Insights
A rare pilomyxoid astrocytoma, a myxoid variant of pilocytic astrocytoma, was identified in a young girl. This aggressive tumor can be misdiagnosed as high-grade glioma, necessitating careful distinction.
Area of Science:
- Neuro-oncology
- Pediatric Pathology
- Neuroradiology
Background:
- Pilocytic astrocytoma (PA) is a common pediatric brain tumor, typically displaying a biphasic histological pattern.
- Accurate diagnosis is crucial as PA has a generally favorable prognosis.
- Distinguishing PA from other glial tumors is essential for appropriate treatment and management.
Observation:
- A case report details a 13-year-old girl with a frontocallosal tumor.
- Magnetic resonance imaging (MRI) revealed a well-defined lesion with necrosis and ring-like contrast enhancement.
- Histopathological examination demonstrated a monophasic tumor with piloid cells in a myxoid background.
Findings:
- The tumor was identified as a pilomyxoid astrocytoma (PXA), an unusual myxoid variant of pilocytic astrocytoma.
- PXA exhibits distinct histological features, differing from the classic biphasic PA.
- The radiological and pathological findings highlight the potential for misdiagnosis as a high-grade infiltrating glioma.
Implications:
- Pilomyxoid astrocytoma is recognized as more aggressive than classic pilocytic astrocytoma.
- Distinguishing PXA from PA and other high-grade gliomas is critical for patient management and therapeutic strategies.
- This case underscores the importance of recognizing rare variants in pediatric neuro-oncology.
