Table 1 Clinical characteristics and radiologic characteristics of the 221 patients with IPNs after esophagectomy

Age(years)

58.17 ± 8.18

58.76 ± 8.22

57.92 ± 8.18

0.992

Sex

0.628

 Male

166

51

115

 Female

55

15

40

History of previous lung infections

0.546

 Yes

9

4

5

 No

212

62

150

Tumor location of ESCC

0.018

 Upper 1/3

21

5

16

 Middle 1/3

133

49

84

 Lower 1/3

67

12

55

Pathologic T category

0.413

 1

55

14

41

 2

50

12

38

 3

104

35

69

 4

12

5

7

Pathologic N category

 < 0.001

 0

119

16

103

 1

52

20

32

 2

18

12

10

 3

32

18

10

Tumor differentiation

0.051

 Well(G1)

80

17

63

 Moderate(G2)

114

37

77

 Poor(G3)

27

12

15

The range of lymph node dissection

0.405

 Mediastinal + abdominal

173

54

119

 Mediastinal + abdominal cervical

48

12

36

Surgery approach

0.731

 VATS

214

63

151

 Open surgery

7

3

4

Neoadjuvant therapy

0.201

 None

192

57

135

 Chemotherapy

19

8

11

 Chemoradiotherapy

10

1

9

Postoperative therapy

 < 0.001

 None

98

14

84

 Chemotherapy

104

41

63

 Chemoradiotherapy

19

11

8

Location of the largest IPN

0.923

 Right upper lobe of the lung

77

22

55

 Right middle lobe of the lung

19

6

13

 Right lower lobe of the lung

47

16

31

 Left upper lobe of the lung

36

9

27

 Left lower lobe of the lung

42

13

29

Time of detection of IPNs ( year)

14.85 ± 15.25

22.86 ± 16.89

11.44 ± 13.13

 < 0.001

  ≤ 1

131

22

109

  > 1, ≤ 2

42

16

26

  > 2

48

28

20

Number of IPNs

 < 0.001

  < 3

131

5

126

  ≥ 3

90

61

29

Size of the largest IPN (mm)

 < 0.001

  ≤ 5

72

1

71

  > 5, ≤ 10

86

21

65

  > 10, ≤ 30

58

40

18

  > 30

5

4

1

Density of the largest IPN

 < 0.001

 Solid nodules

118

60

58

 Ground glass nodules or mixed ground glass nodules

103

6

97

Shape of the largest IPN

 < 0.001

 Round or round-like

158

64

94

 Others

63

2

61

Area of the largest IPN

0.342

 Inner 1/3

29

10

19

 Middle 1/3

90

22

68

 Outer 1/3

102

34

68

Calcification of the largest IPN

 < 0.001

 Yes

27

0

27

 No

194

66

128

Mediastinal lymph nodes enlargement

 < 0.001

 No

189

41

148

 Yes

32

25

7