Table 4.

Proposal of a new scoring system for solitary fibrous tumors of the pleura

Variables	Points
Mitoses ≥4/10 HPF	1
Mitoses <4/10 HPF (or Mitoses missing)	0
Tumor size ≥10 cm	1
Tumor size <10 cm (or tumor size missing)	0
MIB-1 ≥ 10%	1
MIB-1 < 10% (or MIB-1 missing)	0
Necrosis	1
No Necrosis (or necrosis missing)	0

Score interpretation: Each variable scoring a point with a maximum of four points and a minimum of zero points. A missing variable was computed as a value of 0

A score of ≥1 point was associated with adverse outcome with a sensitivity of 88% (95% CI 52–100%) and a specificity of 48% (95% CI 36–60%). (HR 7.03, CI 0.87–56.69, p = 0.067)

A score of ≥2 points was associated with adverse outcome with a sensitivity of 89% (95% CI 52–100%) and a specificity of 83% (95% CI 72–91%). (HR 32.9, CI 4.0–270.9, p = 0.001)

A score of ≥3 points was associated with adverse outcome with a sensitivity of 33% (95% CI 7–70%) and a specificity of 94% (95% CI 86–98%). (HR 4.6, CI 1.2–18.5, p = 0.031)

A score of 4 points was associated with adverse outcome with a sensitivity of 22% (95% CI 3–60%) and a specificity of 100% (95% CI 95–100%). (HR 102.03, CI 8.97–1160.95, p < 0.001)