[Sinonasal hemangiopericytoma: review of four cases].

Aim: The aim of this paper is to discuss, through four cases, the characteristics of sinonasal hemangiopericytoma (SNHP) and its diagnostic difficulties.
Materials and Methods: Description of four recent, histologically proven cases of SNHP. Bibliographic research was conducted using the following principal key word: "sinonasal hemangiopericytoma".
Results: The four patients complained of non-specific rhino-sinusal symptoms. In each case, physical examination revealed a voluminous unilateral polyploïd tumour of the nasal cavities, documented by CT Scan and MRI. Each patient underwent complete tumour resection by endoscopic sinus surgery. Histological and immunohistochemical examination confirmed SNHP diagnosis, although no specific marker was constantly observed. To date, none of the patients has presented with recurrence.
Conclusion: SNHP is of poorly specific clinical and histological presentation. This tumour is difficult to distinguish from solitary fibrous tumour (SFT), with which it is often confused. SNHP is of good prognosis, however lifelong follow-up must be observed.