Malignant Retroperitoneal Hemangiopericytoma: Report of a 73 Years Old Woman and Review of Literature

Introduction: Hemangiopericytomas (HPCs) are rare neoplasms which account for approximately 1% of primary vascular tumors. Case Presentation: We report a 73 years old woman with vague abdominal pain who did not have further significant symptoms and was diagnosed to have retroperitoneal hemangiopericytoma. Discussion: The tumor was initially diagnosed by ultrasound evaluation. MRI showed a lobulated mass at lower lateral quadrant of the abdomen, adjacent to left psoas muscle with small cystic components. Successful surgical resection of the tumor indicated a solitary large encapsulated 10 × 7 × 4 centimeter retroperitoneal multiloculated mass. Subsequent pathologic studies confirmed the tumor to be malignant hemangiopericytoma. The patient is currently well and is evaluated by periodic CT scans.