Hemangiopericytomas are rare mesenchymal neoplasms that were originally thought to arise from the pericytes of Zimmerman, although the true differentiation is unclear. Approximately 15% of all soft-tissue HPCs occur in the head and neck region, where most of them are found within the nose or paranasal sinuses.1Because the clinical and histopathologic features of sinonasal-type HPCs, also referred to as HPC-like tumoror sinonasal glomus tumor, differ from those of soft-tissue HPCs found elsewhere in the body, they are considered a distinct entity.2The World Health Organization classification of head and neck tumors in 2005 suggested that sinonasal-type HPCs should be named glomangiopericytomasbecause of their similarities to glomus tumors.3Patients with these lesions most often present with nasal obstruction or epistaxis in their seventh decade of life.2Clinically, glomangiopericytomas typically appear as polypoid, beefy-red to grayish pink, soft, fleshy masses within the nasal cavity or paranasal sinuses. They can be seen in all age groups and show a slight female predominance.3There are no known etiologic factors associated with the development of glomangiopericytomas.
Pathology Quiz Case 1: Diagnosis. Arch Otolaryngol Head Neck Surg. 2009;135(5):520-523. doi:10.1001/archoto.2009.37-b