Solitary Fibrous Tumor of the Oral Cavity: Clinicopathologic and Immunohistochemical Study of 21 Cases

Abstract

We describe clinical, morphologic, and immunohistochemical features of 21 cases of solitary fibrous tumor presenting in the oral cavity. There were 9 male and 12 female patients with a median age of 51 years (range 37–83). The most common locations included the buccal mucosa (the most common site), lip, maxillary or mandibular vestibule and tongue. Histopathologic examination showed well-circumscribed tumors with two well-defined patterns: the classic pattern with densely cellular areas alternating with hypocellular areas in a variably collagenous, vascular stroma and a more uniformly sclerotic pattern with only subtle classic areas. The spindle-shaped neoplastic cells consistently showed immunoreactivity for antibodies directed against CD34. Five of nineteen cases (26%) were reactive for CD99 and 19 of 19 for Bcl-2. Follow-up information was available in 17 cases and averaged 54 months, with no evidence of recurrence or metastasis in any of these patients. Awareness that solitary fibrous tumor may present in the oral cavity is important so that confusion with other spindle cell neoplasms can be avoided. We also briefly describe the differential diagnosis and compare this series, the largest single series of intraoral SFT, to cases previously reported in the literature.

Large solitary fibrous tumor of the oral cavity—Report of a case

“…Anti-CD34 antibody, which recognizes a 110-kDa transmembrane cell surface glycoprotein found on myeloid progenitor cells, is the most consistent and reliable immunohistochemical marker for SFT [14][15][16]. On the other hand, neoplastic cells are negative for cytokeratins, S-100 protein, epithelial membrane antigen, smooth muscle actin, and Factor VIII [13,17].…”

“…Given the wide range of morphology, SFT can potentially be mistaken for other benign and malignant soft tissue tumors [7,12,14,16]. The differential diagnosis of benign SFT involving the oral cavity includes a variety of lesions, especially fibrous histiocytoma, schwannoma, and, most importantly, hemangiopericytoma [14,17].…”

“…The differential diagnosis of benign SFT involving the oral cavity includes a variety of lesions, especially fibrous histiocytoma, schwannoma, and, most importantly, hemangiopericytoma [14,17].…”

“…The prognosis is based on tumor location, size and histological features considered as malignancy parameters [11]. Two case series of intraoral SFTs, with extensive followup information, showed no signs of local recurrence and/or malignant transformation after treatment [12,14]. In contrast, malignant and metastatic SFTs have been reported to occur in extraoral sites.…”

Solitary Fibrous Tumor with Entrapment of Minor Salivary Gland Tissue: An Unusual Presentation That Requires Exclusion of Pleomorphic Adenoma

“…It has been reported that 13-23% of the pleural SFT are malignant [5]. In contrast, intraoral SFT, has an excellent prognosis associated with a benign clinical behavior [8].…”