Oral Solitary Fibrous Tumor: A Retrospective Clinico-Pathological Study and Long-Term Follow-Up

Abstract

Background and Objectives: This was a retrospective single-center study to analyze and describe the clinical and histological features of all cases of oral solitary fibrous tumor (SFT). Study design: the study included all consecutive cases of oral SFT diagnosed between 2008–2018 at a single tertiary center. Materials and Methods: Clinical data was retrieved from medical charts. The diagnosis of oral SFT was based upon the morphologic features of the lesions, in routine hematoxylin and eosin (H&E) stained sections and confirmed by immunohistochemical analyses including CD34, CD99, Bcl2, and stains for STAT6. Results: Seven cases of oral SFT were found. Of these, three (42%) were in males and four (58%) in females. The age range was 24–63 years (mean 47 ± 13). Four (58%) lesions were located in the buccal mucosa, two (28%) in the labial mucosa and one (14%) on the floor of the mouth. The diameter ranged between 3–50 mm (mean 22 ± 14 mm). All patients were treated with local excision. Follow-up periods were between 2–74 months (mean 41 ± 27). No recurrences were reported. Conclusions: We present a series of oral SFT, which were all non-aggressive in presentation and did not recur after conservative surgery (local excision) over a relatively long follow-up period.

Solitary fibrous tumor of the tongue

“…Therefore, the use of other markers such as CD99 and STAT6 is highly recommended. 5 , 13 In our results, immunohistochemical analysis showed positive labeling for CD34. This glycoprotein is a cell adhesion factor that can be found in different neoplasms; in SFT its expression is observed in 81-95% of cases.…”

“… 9 In our case, CD99 was negative, as pointed out in other studies. 13 Thus, although CD99 has been described as an important alternative marker for SFT, it cannot be considered a predictor for diagnosis. 3 …”

“…9 In our case, CD99 was negative, as pointed out in other studies. 13 Thus, although CD99 has been described as an important alternative marker for SFT, it cannot be considered a predictor for diagnosis. 3 Recent evidence shows that NAB2-STAT6 gene fusions were found by the nuclear expression of the STAT6 protein in SFT cases, which has now become the gold standard marker for diagnosis due to its high sensitivity and specificity.…”

Solitary Fibrous Tumor of Hard Palate: A Case Report and Literature Review

“… 1 According to the literature, although rare, oral cavity is the most common site of occurrence in the head and neck. 1 Approximately 150 cases have been reported until May 2019, 12 and the most common sites of involvement are buccal mucosa, tongue, and lower lip. 1 Incidence of SFT in the palate and specifically in the hard palate is extremely rare, and to the best of our knowledge, only 4 cases of hard palate SFTs have been reported in the literature.…”

“… 2 , 13 Studies believe that intraoral SFTs tend to follow a more benign non-recurring course. 12 However, certain cases of SFTs with benign histological features do recur. Therefore, long-term follow-up of all patients regardless of anatomical locations is highly recommended.…”