Hemangiopericytoma of the skull base masquerading as a middle ear mass: Case report and literature review

Objective: Review the clinical presentation and management of meningeal hemangiopericytomas of the lateral skull base and cerebellopontine angle (CPA), and describe a case of anaplastic hemangiopericytoma of the CPA presenting as a middle ear mass. Study design: Case report and literature review. Case description: A 51-year-old male presented with a one year history of hearing loss, pulsatile tinnitus, and disequilibrium. Physical examination demonstrated a mass in the left middle ear. Magnetic resonance imaging revealed a 4 cm, T1-/T2-isointense, contrast-enhancing mass in the middle cranial fossa. The erosive mass extended into the middle ear and surrounding temporal lobe. A trans-zygomatic approach with a pterional craniotomy exposed a well-encapsulated, highly vascular mass. Manipulation of the tumor resulted in significant hemorrhage. Following removal from the temporal lobe and middle ear, an anterior petrosectomy was performed to remove tumor from the internal auditory canal (IAC) and carotid artery. The facial nerve near the IAC was encased in tumor, and all but a small amount of tumor adherent to the nerve was successfully removed. The final pathologic diagnosis was anaplastic hemangiopericytoma (WHO Grade III). Metastatic workup revealed no extracranial disease, and the patient underwent adjuvant radiation therapy. He continues to do well with only mild disequilibrium at one year follow-up. Conclusions: Hemangiopericytomas are rare, malignant neoplasms that are aggressive and highly vascular. Current management recommendations include excision followed by radiotherapy. Close surveillance is required for patients with anaplastic hemangiopericytoma due to the aggressive nature of this tumor and its propensity for recurrence or metastasis. Keywords: Hemangiopericytoma, Transzygomatic, Skull base, Middle ear mass, Middle cranial fossa, Tumor