Hemangiopericytoma-like tumors of the nasal cavity: a comparison with hemangiopericytoma of soft tissues.

This study compares the published clinical and pathological features of hemangiopericytoma-like intranasal tumors with those of the hemangiopericytomas of other sites. Hemangiopericytoma-like intranasal tumors often originate in a paranasal sinus and extend into the nasal cavity secondarily. They occur most commonly in adults in the sixth and seventh decades of life and clinically mimic allergic polyps. These patients most commonly present with symptoms of nasal obstruction and epistaxis. Microscopically, these tumors demonstrate a vascular architecture, are composed predominantly of spindle cells, and lack nuclear or cytoplasmic pleomorphism, mitotic activity, hemorrhage, or necrosis. Follow-up data suggest that these tumors are unaggressive and are of local consequence only. Hemangiopericytomas of soft tissues usually occur in the retroperitoneum or the thigh and are uncommon in the nasal and paranasal sinuses. They usually present as painless masses. Attention to certain microscopic features of these tumors has led to reasonably good predictions of their behavior based on strict adherence to microscopic criteria. These criteria include the presence or absence of mitotic figures, necrosis, anaplasia, and hemorrhage.