Variable

Total n, (%)

Low malignant potential (Benign) n = 15 (65.2)

High malignant potential (Malignant) n = 8 (34.8)

p-value*

Age at diagnosis, years) (mean, SD)

23

12

62.6 (12.6)

8

65.5 (9.4)

0.58

Gender

23

Male

Female

6 (26.1)

17 (73.9)

3 (20)

12 (80)

3 (37.5)

5 (62.5)

0.334

Symptoms at diagnosis

23

Symptomatic

Asymptomatic

11 (47.8)

12 (52.2)

6 (40)

9 (60)

5 (62.5)

3 (37.5)

0.28

Tumor diameter, cm (mean, SD, range)

21

9.1 (7.3, 1.2 - 27)

13

6.9 (5.3, 1.5 - 16)

8

12.8 (8.8, 1.2 - 27)

0.070

Tumor diametersubgroup

21

<5 cm

>5 cm

8 (38.1)

13 (61.9)

7 (53.9)

6 (46.2)

1 (12.5)

7 (87.5)

0.074

Tumor base

22

Sessile/Inverted

Pedunculated

7 (31.8)

15 (68.2)

4 (28.6)

10 (71.4)

3 (37.5)

5 (62.5)

0.51

Mitoses/10 HPF

21

<4/10 HPF

>4/10 HPF

16 (76.2)

5 (23.8)

13 (100)

0

3 (37.5)

5 (62.5)

0.003

Tumor necrosis

19

Absent

Present

11 (57.9)

8 (42.1)

10 (90.9)

1 (9.1)

1 (12.5)

7 (87.5)

0.001

Tumor hemorrhage

18

Absent

Present

11 (61.1)

7 (38.9)

7 (63.6)

4 (36.4)

4 (57.1)

3 (42.9)

0.58

Nuclear Crowding/overlap

17

Absent

Present

14 (82.4)

3 (17.7)

13 (100)

0

1 (25)

3 (75)

0.006

Infiltration of adjacent structures

21

Absent

Present

18 (85.7)

3 (14.3)

13 (100)

0

5 (62.5)

3 (37.5)

0.042

Stromal Invasion

4

Absent

Present

4 (80)

1 (20)

1 (100)

0

3 (75)

1 (25)

0.80

Vascular Invasion

5

Absent

Present

4 (80)

1 (20)

1 (100)

0

3 (75)

1 (25)

0.80

Encapsulation

20

Absent

Present

1 (5)

19 (95)

0

13 (100)

1 (14.3)

6 (85.7)

0.350

Tumor contour

22

Lobulated

Smooth

12 (54.6)

10 (45.5)

6 (42.9)

8 (57.1)

6 (75)

2 (25)

0.156

Tumor border with adjacent structures

23

Poorly defined

Well defined

1

22

0

15 (100)

1 (12.5)

7 (87.5)

0.348

Pleural pattern

23

Visceral

Parietal

20 (87)

3 (13)

13 (86.7)

2 (13.3)

7 (87.5)

8 (100)

0.73