A case of omental relapse of malignant hemangiopericytoma of the intrapelvic retoperitoneum occurred 13 years after the resection

Abstract

The patient was a 70-year-old female who underwent resection of a malignant hemangiopericytoma of the intrapelvic retroperitoneum following intra-arterial infusion chemotherapy in January 1996, and had a local recurret tumor which was removed with the sacrum in April 1998. Thereafter there had been no evidence of recurrence until 2007 and she decided on her own to stop visiting the hospital. In November 2009, about 13 years after the initial operation, she was found having an intraperitoneal mass demonstrated by ultrasonography for screening medical checkup. Abdominal enhanced CT scan revealed a heterogeneous intraperitoneal mass with clear margin adherent to loop of the small intestine. Relapse of the malignant hemangiopericytoma of the intrapelvic retroperitoneum was diagnosed based on the past histories and abdominal CT findings. In March 2010 resection of the intraperitoneal mass was performed. The intraperitoneal mass was covered with the omentum, and so it was resected with a part of the omentum. Histopathological diagnosis was recurrence of malignant hemangiopericytoma. Since hemangiopericytoma may relapse 10 years or more after the resection, close long-term follow-up is required after the operation.