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Hemangiopericytoma-like intranasal tumors. A clinicopathologic study of 23 cases.

The clinical, microscopic, and gross pathologic features of 23 cases of intranasal hemangiopericytoma-like tumors are reviewed and studied. When in the nasal cavity, these lesions often originated in a paranasal sinus and extended into the nasal cavity secondarily. They occurred most commonly in adults in the sixth and seventh decades of life; there was no significant sex predilection. Twenty-two of the 23 patients were Caucasian. These patients most commonly had symptoms of nasal obstruction and epistaxis. Clinically the lesions were generally thought to represent allergic polyps. Although appearing microscopically as non-differentiated spindle-cell neoplasms, these lesions showed little nuclear or cytoplasmic pleomorphism, minimal mitotic activity, and no necrosis or hemorrhage or other evidence of anaplasia found in malignant tumors. Follow-up data showed no evidence to suggest a malignant or biologically unpredictable lesion. Nineteen of 22 cases followed showed no recurrence regardless of the treatment; those that recurred did so locally. No metastasis or other form of aggressive behavior attributed to hemangiopericytomas in other anatomic locations was seen in this series. Another case, diagnosed as a malignant hemangiopericytoma of the nasal cavity, showed dissimilar and anaplastic histologic features. This case metastasized and is discussed, though not included in this study.