Hemangiopericytoma: Radical resection remains the cornerstone of therapy

Hemangiopericytomas (HPC) are mesenchymal tumors with a propensity towards chronicity and metastasis. This study aimed to reflect a single institution experience with both World Health Organization (WHO) grade II and III HPC. Pathology records from the years 1990-2013 at the University of Washington were searched to identify tumors unequivocally classified as HPC. Electronic chart review was then utilized to collect pertinent patient data. Of the WHO grade II HPC, there were four men and two women (average age 52 years) while the grade III HPC group had eight men and two women (average age 51 years). Sixty-six percent of WHO grade II tumors were located in the middle or posterior fossa as compared to none of the grade III tumors. Survival analysis revealed a significant survival benefit for patients who underwent complete resection (223 months) versus those with subtotal resection (138 months, p<0.05). Factors such as age, sex, the use of up-front radiation, and whether the patient had a recurrence did not show statistical significance related to overall survival or progression free survival. Radiation in the form of external beam radiotherapy given at the time of the first recurrence did trend towards improved progression free survival (56 months) compared to those patients who were not radiated (22 months, p=0.09) All patients with radical resection went on to never have a recurrence. Our results indicate that HPC are tumors with limited response to radiation and best treated with aggressive resection. Future studies will determine whether molecular-based therapies may provide added adjuvant benefit.