Anaplastic pilocytic astrocytoma of the cerebellum presenting with conus medullaris drop metastasis

Due to its rarity, a complete understanding of the clinical behavior, pathogenesis, and diagnostic definition of anaplastic pilocytic astrocytoma (APA) is currently lacking. The optimal clinical management and use of adjuvant therapies has yet to be defined. We present a 64 year-old-female with progressive headaches, dysarthria, and ataxia, who was found to have right cerebellar mass. A gross total resection was achieved through two staged operations. Pathology demonstrated focal areas of necrosis, tumor infiltration, and increased mitotic activity most consistent with APA. Adjuvant chemotherapy and stereotactic radiosurgery were administered. Approximately two years later, the patient presented with symptoms of cauda equina syndrome, and lumbar spine imaging demonstrated a large intradural mass at the conus medullaris with diffuse leptomeningeal enhancement. A biopsy was performed and was consistent with metastatic APA. APA may rarely progress to metastatic disease, most frequently involving the leptomeninges of the posterior fossa and cervical spine. This report represents the first case of metastases distal to the cervicomedullary junction.