Psammomatoid (juvenile) ossifying fibroma of the orbit.

The clinical and pathologic features in 21 cases of a distinctive solitary fibro-osseous lesion affecting the orbit distinguished histologically by the dominance of numerous small round "psammoma-like" ossicles embedded in a cellular benign spindle cell stroma were studied. The patients were predominantly young, and 19 of the lesions were centered on the orbital plate of the frontal bone or ethmoid. A clinical course of slowly progressive symptoms over several years was typical but not uniform. The most common clinical diagnosis was fibrous dysplasia and mucocele. At least nine patients underwent two or more surgical operations; one patient had six recurrences over a 15-year period. There were no known deaths from the tumor, but its potentially massive size can result in considerable morbidity and cosmetic deformity. Although previously referred to as active juvenile ossifying fibroma, the term psammomatoid ossifying fibroma for this lesion is more descriptive and has historical precedence.