Spontaneous hemorrhage associated with a pilomyxoid astrocytoma. Case report.

Pilomyxoid astrocytomas have been identified as a more aggressive variant of pilocytic astrocytomas that occur in infants and in young children. These tumors are characterized by a perivascular arrangement of pilocytic cells that has a monomorphous architecture with uniform, elongated bipolar cells loosely ranged within a prominent myxoid background. The authors present the case of a 24-year-old man with a pilomyxoid astrocytoma of the temporal lobe, who presented with a hemorrhage. The patient underwent gross-total tumor resection, and no evidence of residual or recurrent tumor was found on magnetic resonance images at the 6-month follow-up examination. The occurrence of a pilomyxoid astrocytoma in an adult suggests that this tumor is not limited to children. The tumor described in this report is unique because of its presentation with a hemorrhage, which has not been previously described in cases of pilomyxoid astrocytomas and is rarely found in those of pilocytic astrocytomas. Although this tumor predominantly exhibited the pattern of a pilomyxoid astrocytoma, there was a small focus of pilocytic astrocytoma, indicating that there is a spectrum of histological components found in these tumors and that certain elements may be associated with a more aggressive phenotype. In this paper the authors review the literature on pilomyxoid astrocytomas and discuss the unique aspects of this particular tumor presentation.