Orbital Hemangiopericytoma: Clinical and Morphologic Features

Abstract

To report the clinical and histopathologic features of orbital hemangiopericytoma. We review the clinical and histopathologic features in seven patients. Ultrasonography, computed tomography, and magnetic resonance imaging defined the location and extent of the tumor in each patient but did not disclose pathognomonic features for the specific diagnosis of hemangiopericytoma. The predominating histopathologic feature of each tumor was a mixed pattern of ovoid cells and sinusoidal space formations. Five patients showed mild to severe cellular atypia; three had obvious pleomorphism and increased number of abnormal mitotic figures. Tumor cells disclosed cytoplasmic reactivity for vimentin but in five cases were negative for other immunologic markers. Six patients received surgical treatment with an attempt for total removal of the tumor; one had biopsy and radiation therapy. In two patients, radiation therapy was given in addition to tumor removal with orbital exenterations. Three patients died with recurrent and metastatic disease, and four patients are alive without tumor for a follow-up period ranging from 3 to 9 years. Orbital hemangiopericytoma may behave as a malignant tumor, leading to local recurrence or metastasis, or both. Clinical and histopathologic findings should be considered jointly to evaluate the clinical course; histopathologic findings alone are not sufficient to predict the biologic behavior of this tumor.