Management of Solitary Fibrous Tumour of the Buccal Mucosa
Complete surgical excision with wide margins is the definitive treatment for solitary fibrous tumour of the buccal mucosa, typically performed via transoral approach. 1, 2
Surgical Approach
The gold standard treatment is surgical removal with wide margins 1. For buccal mucosa lesions, a transoral approach through the buccal mucosa is the preferred technique 2. This approach offers several advantages:
- Produces superior aesthetic outcomes
- Reduces morbidity from nerve, vascular, and salivary gland injury
- Promotes more effective healing compared to external approaches 2
Even when the tumour extends into adjacent spaces like the infratemporal fossa, transoral excision remains feasible and appropriate 2.
Diagnostic Confirmation
Before proceeding with definitive surgery, confirm the diagnosis through:
- Excisional or incisional biopsy with histopathological examination
- Immunohistochemistry showing: STAT6 (most specific), CD34, Bcl-2, and CD99 positivity 1, 3, 4, 5
The STAT6 marker is particularly critical as it distinguishes SFT from other spindle cell lesions that can appear morphologically similar 3, 6.
Risk Stratification
Assess the mitotic index and histological features to determine recurrence risk:
- Low risk: <4 mitoses per 10 high-power fields
- Intermediate risk: 4-6 mitoses per 10 HPF
- High risk: >6 mitoses per 10 HPF 4
Most oral cavity SFTs are low-risk with mitotic rates of 0-1/10 HPF 4, 5.
Adjuvant Therapy Considerations
While surgery alone is typically curative for oral SFTs, radiotherapy should be considered for SFTs given their documented radiosensitivity 7, 8, 9. This is particularly relevant if:
- Margins are microscopically positive (R1 resection)
- The tumour is in a critical anatomic location where re-excision would cause significant morbidity
- There are high-risk histological features
The ESMO guidelines specifically note that SFT is among the histological types gaining greatest benefit from radiotherapy 9.
Follow-Up Protocol
Long-term surveillance is mandatory due to the risk of late recurrence, even in histologically benign tumours 1, 6:
- First 2-3 years: Every 3-4 months with clinical examination and imaging
- Years 3-5: Every 6 months
- After 5 years: Annually, potentially lifelong given documented late recurrences 8
Imaging should include the primary site and chest imaging to detect potential metastases, though metastatic disease is rare in oral cavity SFTs 5.
Key Clinical Pitfalls
Do not confuse SFT with other spindle cell lesions on histology alone—immunohistochemistry is essential 3. The microscopic characteristics can mimic malignant mesenchymal neoplasms, making STAT6 staining critical for accurate diagnosis.
Do not assume benign behavior based on histology alone—even low-grade SFTs require long-term follow-up as recurrence can occur years after initial resection 6.
For advanced or metastatic disease (extremely rare in buccal mucosa), antiangiogenic agents like pazopanib or sunitinib show activity 7, 10, though this scenario is unlikely in primary oral cavity presentation.