TERT promoter mutations in solitary fibrous tumour

Abstract

TERT promoter mutations were more frequent in SFT with higher risk of metastasis, but TERT promoter mutation status was not a reliable predictor of clinical outcome by itself. However, mutations in the TERT promoter may be useful in further stratifying patients with intermediate risk tumours.

Controversial issues in soft tissue solitary fibrous tumors: A pathological and molecular review

“…Generally, high mitotic count with an overall agreement of ≥4/10 HPFs denote the strongest single prognosticator of malignant behavior . This was confirmed in a large series by Kim et al where they demonstrated that only mitoses (≥4/10 HPFs) remained predictive in multivariate analysis, although other factors (large tumor size, high tumor cellularity and pleomorphism or tumor necrosis) were associated with both recurrence and disease‐specific mortality.…”

“…Recent reports have suggested that TERT promoter mutations (Fig. d) are associated with poor prognosis in SFTs . Moreover, TERT promoter mutations have been strongly associated with higher risk classifications.…”

“…Solitary fibrous tumor (SFT) is a mesenchymal tumor with uncertain differentiation and intermediate malignant potential . SFTs can arise at any location (pleural or extrapleural) and display a wide histopathological spectrum, frequently with hemangiopericytoma‐like vessels . Several other histological patterns have also been described, including round cell, giant‐cell‐containing, epithelioid, myxoid, fat‐forming, pleomorphic and dedifferentiated variants .…”

“…Although several publications have discussed the histological, clinical or molecular criteria for malignancy in SFT, no feasible determinant of malignancy has yet been established for practical use . This situation has prompted the creation of several risk stratification systems, incorporating not only histological factors, but also clinical or radiological parameters . Nevertheless, few studies have evaluated the role of molecular alterations in malignant SFTs compared to nonmalignant SFTs .…”

“…SFTs frequently exhibit a patternless or storiform proliferation of spindle/ovoid‐shaped tumor cells (Fig. ) with hemangiopericytoma‐like‐vessels and a haphazard arrangement of bland tumor cells with intermixed collagenous stroma . Tumor cells reveal strong nuclear and diffuse STAT6 immunoreactivity with variable CD34 and Bcl2 immunoexpression (Fig.…”