A rare case of solitary fibrous tumor of the temporal region: 7-year-follow-up clinical-radiographic evaluation and literature review

Solitary fibrous tumor is a rare spindle-cell neoplasm of mesenchymal origin. In head and neck region, the tumors present slow-growing masses, often with local compressive symptoms. Although it is generally benign, malignant variants have been identified. The radiological diagnosis of solitary fibrous tumor is usually based on computer tomography and/or magnetic resonance imaging. Microscopically, a solitary fibrous tumor is characteristically a circumscribed neoplasm composed of variably cellular and patternless distributions of bland spindle and ovoid cells within variably collagenous stroma that frequently shows areas of dense hyalinisation, as well as interspersed large branching or “staghorn”- shaped thin-walled vessels. Immunohistochemical staining is very effective to distinguish solitary fibrous tumors from other fibroblastic tumors. Recently, NAB2–STAT6 gene fusion derived from inv12 (q13q13) has been reported as the genetic hallmark of solitary fibrous tumor. Complete local surgical excision appears to be the treatment of choice for solitary fibrous tumor of the head and neck region. Recurrence was reported in 5% of cases. The median recurrence-free interval was 36.5 months. We report the case of a solitary fibrous tumor of the temporal region, surgically excised and with no clinical and/or radiological signs of recurrence after 7 years of follow-up.