Abstract
Aims
Solitary fibrous tumours (SFTs) are rare neoplasms often described arising from the pleura, however extrapleural SFTs occur. They are often histologically bland, but may recur and metastasise. Distinction from mimics can be problematic and behaviour is difficult to predict. Recent publications have shown promising results with an immunostain for nuclear expression of STAT6. We aimed to assess the usefulness of STAT6 for diagnosis and investigate the possibility of differential labelling based on tumour location and prognosis.
Methods
Fifty cases with a diagnosis of SFT (1999–2014) were assessed for STAT 6 labelling. Data collected included tumour location, size and potential for malignancy based on histological features assessed in the initial report.
Results
Of 50 cases (22 M/28F; average size ~414 cm3), 2/3 were extra-thoracic and 1/3 intra-thoracic SFTs; 2/3 were reported as being histologically bland on diagnosis (1/3 malignant/uncertain). Five cases initially diagnosed as benign have developed tumour recurrence 1–8 years post diagnosis. Nuclear labelling for STAT 6 was seen in 92%, regardless of location, size, histological prognostic classification or clinical behaviour.
Conclusion
These findings support the utility of STAT6 as an adjunct in diagnosis of SFT irrespective of site, but do not support a role for prognosis.
Solitary fibrous tumours (SFTs) are rare neoplasms often described arising from the pleura, however extrapleural SFTs occur. They are often histologically bland, but may recur and metastasise. Distinction from mimics can be problematic and behaviour is difficult to predict. Recent publications have shown promising results with an immunostain for nuclear expression of STAT6. We aimed to assess the usefulness of STAT6 for diagnosis and investigate the possibility of differential labelling based on tumour location and prognosis.
Methods
Fifty cases with a diagnosis of SFT (1999–2014) were assessed for STAT 6 labelling. Data collected included tumour location, size and potential for malignancy based on histological features assessed in the initial report.
Results
Of 50 cases (22 M/28F; average size ~414 cm3), 2/3 were extra-thoracic and 1/3 intra-thoracic SFTs; 2/3 were reported as being histologically bland on diagnosis (1/3 malignant/uncertain). Five cases initially diagnosed as benign have developed tumour recurrence 1–8 years post diagnosis. Nuclear labelling for STAT 6 was seen in 92%, regardless of location, size, histological prognostic classification or clinical behaviour.
Conclusion
These findings support the utility of STAT6 as an adjunct in diagnosis of SFT irrespective of site, but do not support a role for prognosis.
| Original language | English |
|---|---|
| Pages (from-to) | S62 |
| Number of pages | 1 |
| Journal | Pathology |
| Volume | 47 |
| Issue number | S1 |
| DOIs | |
| Publication status | Published - 2015 |
| Event | 39th Annual Scientific Meeting of the Australasian Division of the International Academy of Pathology - Brisbane Convention & Exhibition Centre, Brisbane, Australia Duration: 30 May 2014 → 1 Jun 2014 |
Keywords
- STAT6
- fibrous tumours
- SFTs