Nasal septal hemangiopericytoma-like tumor: a case report with an immunohistochemical study.

Nasal hemangiopericytoma-like (HPCL) tumor is a rare vascular tumor and should be differentiated from typical hemangiopericytomas (HPCs). This study reports the case of an HPCL tumor in a 77-year-old man with histological and immunohistochemical features. After preoperative evaluation of the blood supply, the dark-red right intranasal tumor was resected completely via the right maxillary sinus. The final histopathological diagnosis was HPCL tumor based on several stains: vimentin (+), alpha-SMA (+), etc. Moreover, there were few p53 (+) cells and the Ki-67 and topoisomerase IIalpha labeling indices were both under 5%. These findings indicated that this tumor was a low-grade malignancy. The immunohistochemical investigations used are useful for making the diagnosis of HPCL tumor and determining the treatment, malignancy, and prognosis.