Cerebellar Pleomorphic Xanthoastrocytoma with BRAF V600E Mutation

BACKGROUND: Pleomorphic xanthoastrocytoma (PXA) is a rare type of astrocytoma with a peak incidence from 10 to 19 years of age. PXA is found most commonly in the supratentorium. When it is present in atypical areas such as the infratentorium, it is often overlooked as a potential differential diagnosis. CASE DESCRIPTION: This report discusses the case of an 18-year-old woman with a pure PXA in the left cerebellum. The case consists of interesting pathologic and molecular features which do not align with the literature about PXA: a positive finding for BRAF V600E mutation and a negative finding for cluster of differentiation 34 expression. A review of pure PXA cases in the infratentorium has also been completed. CONCLUSIONS: To our knowledge, this is the first case of PXA in the infratentorium with BRAF V600E mutation. The case also highlights the clinical relevance of including PXA as a differential diagnosis for lesions of the infratentorium.