Multicentric Hemangiopericytoma of Posterior Fossa: A Rare Case and Review of Literature

Hemangiopericytomas (HPCs) are rare aggressive tumors, thought to comprise 2 to 3% of all primary meningeal tumors and 0.4% of all intracranial tumors.1–5 It was first reported by Stout and Murray6 and occurs mostly in soft tissue, including brain meninges primarily. Histologically, intracranial HPC arises from malignant transformation of Zimmerman’s pericytes, supportive cells that help form the walls of meningothelial capillaries.1,2,6 HPC is considered a World Health Organization (WHO) grade II neoplasm, with anaplastic variants classified as grade III.4 Because HPC closely mimics meningioma in clinical and radiographic presentation, histologic confirmation is the only definitive means of distinguishing the diagnosis. Even after aggressive initial management combining gross total resection (GTR) with adjuvant external beam radiotherapy (EBRT), recurrence rates have been as high as 30%.3 These tumors have high propensity toward progression making optimal primary treatment of HPC a difficult endeavor. Case Report