A Case of Malignant Hemangiopericytoma of the Retroperitoneum Successfully Treated by Combined Modality Therapy

Abstract

A 17-year-old Japanese youth was admitted to our hospital with complaints of abdominal distension and both pain and numbness in the right lower extremity. Computed tomography and magnetic resonance imaging on admission revealed a huge tumor in the right retroperitoneum. A biopsy specimen was taken by laparotomy and it revealed malignant hemangiopericytoma. After radiation by Linac (total 40 Gy) and chemotherapy with cisplatin (total 320mg), the tumor was reduced by 48%, to a size that would make surgical extirpation possible. After ascertaining that the tumor had not increased in size during the next 5 months, we went ahead with our original plans to perform extirpation. As a preliminary procedure to minimize bleeding during the operation, we selectively embolized of 3 right lumbar arteries and a branch of the right internal iliac artery, which were feeder vessels of the tumor. Three days later, surgical extirpation was carried out. After receiving postoperative chemotherapy, the patient was discharged from the hospital, and was followed in the Outpatient Clinic. There were no signs of recurrence or metastasis during the 13 months after the first chemotherapy, which means the patient survived for at least 1 year and 9 months after admission. Malignant hemangiopericytoma of the retroperitoneum is still rare in Japan, and the prognosis is very poor. To our knowledge, no patients have survived 2 years or longer. What makes this case noteworthy is that combined modality therapy appears to be an effective treatment for malignant hemangiopericytoma.