Solitary fibrous tumors (SFTs) of the head and neck are uncommon. Lesions previously diagnosed in the head and neck as hemangiopericytomas (HPCs), giant cell angiofibromas (GCAs), and orbital fibrous histiocytomas (OFHs) are now recognized as within the expanded spectrum of SFTs. To better understand the clinicopathologic profile of head and neck SFTs, we performed a multi-institutional study of 88 examples. There was no sex predilection (F:M ratio 1.2), and the median patient age was 52 years (range: 15 to above 89 y). The sinonasal tract and orbit were the most common sites involved (30% and 25%), followed by the oral cavity and salivary glands (15% and 14%). Original diagnoses included HPC (25%), SFT (67%), and OFH (6%), with 1 SFT and 1 OFH noted as showing GCA-like morphology. On review, the predominant histologic pattern was classic SFT-like in 53% and cellular (former HPC-like) in 47%; lipomatous differentiation (8%) and GCA-like pattern (7%) were less prevalent. Subsets demonstrated nuclear atypia (23%), epithelioid morphology (15%), or coagulative necrosis (6%). Infiltrative growth (49%) and osseous invasion (82%) were prevalent among evaluable cases. Of the 48 SFTs with follow-up (median: 43 mo), 19 showed recurrence (40%). Of these, 4 patients were alive with disease and 4 dead of disease. Size and mitotic rate were negative prognosticators using a joint prognostic proportional hazards regression model. Three patients experienced metastasis, to lungs, parotid, bone, and skull base, including one case showing overtly sarcomatous “dedifferentiation.” As a group, SFTs present in a wide anatomic and morphologic spectrum in the head and neck. Only rare examples metastasize or cause death from disease. However, the fairly high local recurrence rate underscores their aggressive potential and highlights the importance of prospective recognition.
*Departments of Pathology and Surgery, VCU School of Medicine, Richmond, VA
†Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA
§Biostatistics Facility, University of Pittsburgh Cancer Institute
**Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA
∥Department of Pathology, SUNY Upstate Medical University, Syracuse, NY
Departments of ‡Pathology
††Oral and Maxillofacial Surgery, University of Michigan Health System, Ann Arbor
#Department of Urology, Henry Ford Health System, Detroit, MI
R.R.S. and J.B.M. share senior authorship for this work.
A preliminary analysis of this project was presented as an oral proffered paper at the 102nd United States and Canadian Academy of Pathology Annual Meeting in Baltimore, MD, March 2013, for which it was awarded the 2013 Vincent Hyams Award from the North American Society of Head and Neck Pathology.
Conflicts of Interest and Source of Funding: Supported in part by SPORE Grant U54CA168512 to R.M.P and used the UPCI Biostatistics Facility that is supported in part by award P30CA047904. The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article.
Correspondence: Steven C. Smith, MD, PhD, Department of Pathology, Virginia Commonwealth University School of Medicine, 1200 E. Marshall Street, P.O. Box 980662, Richmond, VA 23298 (e-mail: firstname.lastname@example.org).