Pleomorphic Xanthoastrocytoma with Anaplastic Features: Retrospective Case Series

OBJECTIVE: Pleomorphic xanthoastrocytoma (PXA) is a unique meningocerebral glioma with a relatively favorable prognosis. PXA also possesses a variant with anaplastic features (aPXA), which is associated with poor outcomes. To date, few studies have examined the clinicopathologic importance of these anaplastic features. METHODS: From 1999-2012, 8 patients with aPXA were treated at the University of California, San Francisco, California, United States. Cases were reconfirmed by neuropathology, and clinical information regarding patient demographics, tumor characteristics, and treatment outcomes was assembled. Tumors were classified as aPXA according to the World Health Organization diagnostic criteria established in 2007. RESULTS: There were 5 female and 3 male patients in our cohort, ranging in age from 4-74 years at initial diagnosis. Seizure was the most common presenting symptom (50%), and the majority of tumors arose in the frontal or temporal lobes (88%). Six patients received subtotal resection (STR), and all suffered from progression despite adjuvant radiotherapy and chemotherapy. Median time to progression was 20 months, with a 1-year progression-free survival rate of 57%. Three aPXA patients expired with a median survival of 87 months. Four patients developed disseminated disease. Three of 8 (38%) showed BRAF(v600) mutation. CONCLUSION: aPXA is associated with poorer clinical outcomes compared with PXA. Gross total resection should be the goal of initial treatment. It remains unclear whether adjuvant radiation and chemotherapy are able to prevent progression or dissemination. Long-term monitoring of all patients is a critical step in management due to the potential for tumors to transform into higher-grade lesions.