Clinicopathologic and immunohistochemical features of five new cases of solitary fibrous tumor of the oral cavity

Objective. To describe the clinicopathologic and immunohistochemical features of five cases of oral solitary fibrous tumor. Study Design. Clinical data were collected from charts of two oral pathology laboratories of Latin America. All cases were evaluated by conventional hematoxylin and eosin staining and an extended immunohistochemical panel comprising vimentin, CD34, CD99, bcl-2, HHF-35, smooth muscle actin, calponin, S-100 protein, h-caldesmon, and Ki-67. Results. The study included 1 male (20%) and 4 female (80%) patients, with a median age of 43 years. The most common affected site was the buccal mucosa (40%). Tumors were characterized by proliferation of spindled and ovoid cells in a variably vascular and collagenized stroma. All tumors were positive for vimentin, CD34, bcl-2, and CD99. Recurrence was not observed after complete surgical enucleation. Conclusions. Oral solitary fibrous tumors usually appear as well-delimited submucous nodules with a firm-rubbery consistency and covered by intact mucosa. Immunoreactivity for CD34, bcl-2, and CD-99 is helpful to confirm the diagnosis.