Primary epidural hemangiopericytoma in the sacrum: a rare case and literature review.

Hemangiopericytoma (HPC) is an uncommon highly vascular neoplasm that originated from Zimmerman's pericytes which surrounds the endothelial tissue. Primary epidural HPC of the sacrum is extremely rare. We reported an unusual case of primary epidural malignant HPC of the sacrum that invaded vertebral bone and caused rectum compression in a 57-year-old male for the first time. The patient presented progressive low back pain and ribbon-like stool over 3 months. The surgical intervention involved sacrectomy and en bloc resection of the tumor. We described the clinical, radiological, and histological features of this tumor and reviewed the literature.