A Unique Case of Recurrent Intracranial Extravascular Papillary Endothelial Hyperplasia After Gross Total Resection and Brachytherapy

Background: Extravascular papillary endothelial hyperplasia (EPEH) is an extremely uncommon form of papillary endothelial hyperplasia characterized by an exuberant reactive endothelial proliferation in areas of extravascular hemorrhage rather than within the vascular lumen. Intracranial EPEH is known to develop after radiosurgery in patients with intracranial neoplasms, suggesting a causative relationship between radiotherapy and the development of EPEH. Intracranial EPEH is typically treated with surgical resection; to date, there have been no reported cases of EPEH recurrence after gross total resection. Case Description: A 75-year-old man with a history of atypical meningioma presented to our hospital with progressive right upper and lower extremity weakness. Eight and a half years before admission, he had undergone surgical resection and stereotactic radiosurgery for a World Health Organization grade II meningioma. Several years later, he experienced a mass in the prior resection cavity and was subsequently treated with gross total resection and cesium-131 brachytherapy seeds. Postoperative pathologic examination of the resected tissue at that time showed EPEH with no evidence of recurrent atypical meningioma. On this admission, magnetic resonance imaging showed a recurrent mass in the area of prior resection, at which time the patient underwent a third craniotomy and gross total resection. Postoperative histopathologic examination showed findings consistent with the diagnosis of recurrent EPEH. Conclusions: This case report is the first known recurrence of intracranial EPEH occurring after gross total resection and brachytherapy.