Pelvic hemangiopericytoma. An unusual location of a vascular tumor.

Background: The hemangiopericytoma is an uncommon vascular tumour. We report a case of interest because of its rarity, size and location.
Case Report: We present the case of a 63-year-old woman who consulted for abdominal pain. TAC, MRI and arteriography showed a pelvic mass occupying Douglas' space, displacing the uterus, bladder and sigma, with vascularisation relative to the inferior mesenteric artery and both hypogastric arteries. The vascularity of the tumour itself was selectively embolised before the mass was resected. There were no intra- or postoperative complications. Pathology confirmed the diagnosis of hemangiopericitoma. The patient is being monitored as an outpatient, with no signs of recurrence to date.
Discussion: The hemangiopericytoma is a tumour of the pericyte cells so it can occur in any location. The pelvic location is exceptional. The tumour may appear as nonspecific abdominal pain, show signs of compression of adjacent organs or occasionally be associated with paraneoplastic syndromes. The diagnosis is suspected via CT and angiography findings, but confirmation is only made by analysing the surgical specimen. The treatment of choice is surgery, in some cases after preoperative embolisation of the vascularisation of the mass. There is no agreement on chemo/radiotherapy as the primary treatment for hemangiopericytoma, although adjuvant radiation therapy has been found to improve local control and reduce recurrences. The prognosis is good if complete resection is achieved, with five- and 10-year survival rates between 70 and 80%, depending on the series.