Giant cell angiofibroma, a variant of solitary fibrous tumor, of the orbit in a 16-year-old girl.

A 16-year-old girl presented with diplopia and gradual-onset, painless proptosis of the left eye. Orbital CT showed a well-circumscribed, enhancing, extraconal mass in the superior orbit, and the surgical excision was performed. Histopathology was interpreted as capillary hemangioma. Five years later, her symptoms recurred, and she was referred to the Oncology Service, Wills Eye Institute. Repeat orbital MRI showed a well-defined, extraconal mass with loculated areas of enhancement in the left orbit superonasally. Complete surgical excision was performed. Histopathologic examination showed benign, patternless spindle-cell proliferation with prominent intrinsic vascularity and multinucleated giant cells, consistent with giant cell angiofibroma, a variant of solitary fibrous tumor. There was intense immunoreactivity for CD34. After 20 months follow-up, there was no recurrence or development of metastasis. Giant cell angiofibroma, a variant of solitary fibrous tumor, is a rare orbital tumor that presents as a well-circumscribed, enhancing mass and can be found in children.