Papillary endothelial hyperplasia associated with cortical dysplasia.

We report a unique case of papillary endothelial hyperplasia (PEH) presenting as a subcortical mass lesion intimately associated with focal cortical dysplasia (CD) and consider a possible causal relationship. A 6-year old girl presented with a 6-month history of a painless, frontoparietal skull "bump" associated with slowly progressive localised bossing followed by a 4-month history of absence attacks. Magnetic resonance imaging (MRI) revealed an adjacent parietal enhancing mass lesion beneath abnormal appearing cortex. A haemorrhagic vascular lesion with histology consistent with that of papillary endothelial hyperplasia was completely resected. Biopsies of the adjacent cortex showed CD. The patient has been symptom free post-surgery for 12 months with no MRI evidence of recurrence. Intracranial PEH is very rare and, in contrast to extracranial examples, half of the reported cases lacked a demonstrable vascular origin. Given that CD may be associated with intrinsic capillary hypervascularity, vascular malformations and tumours (e.g. dysembryoplastic neuroepithelial tumour) of a potential hypervascular or haemorrhagic nature, the association between PEH and CD may not be incidental. The abnormal vascularity not uncommonly found in CD may predispose to haemorrhage and/or thrombosis, the organisation of which may rarely be complicated by PEH. Alternatively, PEH and CD may both represent local, independent complications of a pre-existing vascular event or trauma.