Single-agent carboplatin for a rare case of pilomyxoid astrocytoma of the spinal cord in an adult with neurofibromatosis type 1

Abstract

Introduction: Pilomyxoid astrocytoma (PMA) is a rare and more aggressive variant of pilocytic astrocytoma, which usually affects young children and is most often located in the hypothalamic/chiasmatic region. The association of PMA with underlying genetic disorders is not well known. Methods: We identified a 23-year-old woman with a PMA of the spinal cord who was simultaneously diagnosed with neurofibromatosis type 1. Diagnosis of neurofibromatosis type 1 was made clinically and confirmed with genetic testing that revealed a heterozygous one-amino-acid deletion (c.2970-2972 delAAT) in exon 17 of the NF1 gene, which is correlated with a milder phenotype. The patient underwent a partial surgical resection of the spinal cord tumor followed by adjuvant carboplatin 560 mg/m2 every 4 weeks. Radiation was avoided due to risks associated with neurofibromatosis type 1. Results: At the 11-month follow-up, the patient maintained a partial radiographic response as well as complete resolution of her neurologic deficits. Conclusion: To our knowledge, this is the first reported case of an adult patient with neurofibromatosis type 1 and a spinal cord PMA. Single-agent carboplatin was effective and well-tolerated.