Solitary Fibrous Tumors in the Head and Neck: New Insights and Implications for Diagnosis and Treatment

Objectives: The solitary fibrous tumor (SFT) is a potentially malignant spindle cell neoplasm of mesenchymal origin that was originally described as a thoracic lesion originating from pleural tissue. Recently, numerous extrapleural sites of origin have been described, frequently affecting the head and neck region. The purpose of this article is to focus on a formerly underestimated neoplasm and to highlight its appearance in the head and neck region. Methods: The authors present 2 illustrative cases, including what is probably the first reported case of an SFT arising in the human tonsillar fossa, and give a clinical and pathological literature review. Results: The clinical, histologic, and radiologic features are presented, and the surgical treatment is described. The international medical literature concerning SFTs in general and SFTs of the head and neck in particular is reviewed, and the changing concept of SFTs and hemangiopericytomas is discussed on the basis of the updated World Health Organization classification of soft tissue tumors. Conclusions: It is nowadays recognized that the large majority of lesions formerly classified as hemangiopericytomas are, in fact, variants of SFTs. Although still a rare occurrence, SFTs have become increasingly recognized, and clinicians should be aware of their presentation.