Solitary fibrous tumour of the oral cavity: An update

Abstract

BackgroundSolitary fibrous tumour is an unusual neoplasm of the oral cavity that is sometimes not clinically distinguishable from other lesions. The purpose of the present study was to review the clinical, microscopic and molecular aspects of malignant and benign solitary fibrous tumour of the oral cavity currently available in literature.MethodsFor our review, an electronic search was performed using PubMed, Scopus, Ovid/MedLine, Web of science and ProQuest Dissertations and Theses Global database.ResultsA total of 74 publications reporting 150 cases were included. Oral solitary fibrous tumours are most frequently described as submucosal, well‐circumscribed, asymptomatic nodule, more prevalent in females in their fourth to fifth decades of life. Buccal mucosa is the most commonly affected site by the benign tumour variant, whereas the tongue is the most common location affected by the malignant form of the neoplasm. Most of the lesions were treated by conservative surgery. One recurrent malignant tumour and one metastasis are reported.ConclusionAsymptomatic normal‐coloured submucosal nodules located in the buccal mucosa and tongue in adult patients are suggestive of oral solitary fibrous tumour, but only a careful microscopic examination can differentiate benign from malignant variants and the use of immunohistochemistry (CD34, Bcl‐2, CD99 and STAT6), and cytogenetic studies (NAB2‐STAT6) contribute significantly to confirm the diagnosis of solitary fibrous tumour in difficult cases.

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

“…Two cases in the present series also reported previous trauma to the area of the lesion, although this may not necessarily prove a cause-and-effect relationship. In previous reports, the buccal mucosa was the most affected site [9,11,16]. This fact was confirmed in the present series as well, with four of the seven cases occurring in the buccal mucosa.…”

“…In this study we described seven cases of oral SFT, of which all were treated with conservative local excision with a follow-up time of up to 74 months, with no recurrence reported. In the present study, SFT was diagnosed in a wide age group from young adults to elderly (24-63 years), an age variance consistent with previous publications [9,15,16].…”

“…During the present study period, a total of 17 head and neck cases were diagnosed in our institution (including the 7 oral cases represented in this study), of which 10 can be classified as carrying a potential risk for metastasis and recurrence by the aforementioned criteria: all 10 cases showed hypercellularity, 5 out of 10 cases showed nuclear atypia, 2 cases showed necrosis, and a mitotic count of 4/10 HPF or higher was observed in 3 cases; resulting in 1 case being classified as grade 1, 7 as grade 2, 1 as grade 3, and 1 classified as 2-3. Nunes et al, in his literature review (published in early 2020) of SFT in the oral cavity reports that out of 150 cases published 136 (90.7%) were benign and 14 (9.3%) were malignant [9]. Also out of 153 head and neck cases reported in a literature review by Cox et.…”

“…SFT exhibits non-specific clinical manifestation, and would be in the differential diagnosis together with other soft-tissue submucosal lesions (such as neurofibroma, schwannoma, myofibroma, leiomyoma, and salivary gland neoplasms), making the clinical recognition of oral SFT very unlikely [9,11]. Final diagnosis is based on histopathological features and confirmed by immunohistochemistry.…”

“…Oral SFT is a rare entityonly 150 cases were reported until May 2019, and most were case reports with only a few case series. Out of the 150 oral SFT reported cases, only 14 (10%) were at the time classified as malignant [9]. In the latest edition of the WHO Classification of Tumors [10], the SFT's classification as benign or malignant has been excluded, instead a set of criteria to predict the risk of metastasis has been included.…”