Report of one case and review of the literature

The new WHO classification of soft tissue tumours, has introduced some changes in the nomenclatura of pericytic lesions but also in its clinicopathologic definition. Among this kind of lesions, sinonasal-type hemangiopericytoma is considered a tumor with true pericytic differentiation. It is a upper aero-digestive tract neoplasm, slightly commoner in women than men, and occurs in all age groups but it is more commonly seen in the 6th and 7th decades of life. The most frequent clinical presentation is airway obstruction and/or epistaxis and there are no known etiologic factors linked with its development. In general, sinonasal-type hemangiopericytoma is an indolent tumor and local recurrence results from inadequate surgical excision. Tumors with an aggressive behaviour, locally destructive or metastatic, have been occasionally reported in the literature. We describe a case of this uncommon tumor with the characteristics clinical and pathologic findings in this lesion. A 85-year-old woman presented with a 2-year history of epistaxis. The tumor involved the left nasal cavity and also the homolateral paranasal sinuses, it was polypoid and the patient was treated by endonasal endoscopic surgery with a complete resection. Microscopically, it was constituted from sheets of uniform cells with a ovoid nuclei and indistinct cytoplasm distributed around characteristic hyalinized vascular spaces. Nuclear pleomorphism was absent and mitotic figures were identified a very low rate. The tumor was immunoreactive with vimentin, muscle specific actin, smooth muscle actin and CD34. After two-years of follow-up, the patient is alive and without evidence of disease.