Table 2 Comparison of clinicopathological factors in the presence or absence for metastasis or recurrence of parathyroid carcinoma

Age, y

53

[47, 65]

57.0

[45.5, 68]

NS

Sex, male/female

9/24

27.3/72.7

2/3

40.0/60.0

NS

Preoperative serum calcium level, mg/dl

11.4

[10.7, 12.7]

11.6

[11.1, 15.9]

NS

Preoperative intact PTH, pg/ml

253.0

[171.4, 330.4]

195.0

[102.5, 1243]

NS

Tumor size, mm

28.0

[16.5, 35.7]

35.0

[25, 40]

NS

Surgical procedure

 Parathyroidectomy/en bloc

15/18

45.5/54.5

2/3

40.0/60.0

NS

Lymph node dissection, yes/no

11/22

66.7/33.3

2/3

40.0/60.0

NS

Postoperative radiotherapy, yes/no

1/32

3.0/97.0

1/4

20.0/80.0

NS

Tumor weight, mg

1800

[1180, 8010]

16,735

[5560, 28950]

0.0343

Histological component, chief cell/oxyphil cell

27/6

81.8/18.2

4/1

80.0/20.0

NS

Capsular invasion, + 

30

90.9

5

100.0

NS

Vascular invasion, + 

17

51.5

4

80.0

NS

Necrosis, + 

2

6.1

3

60.0

0.0108

Ki-67 index, %

0.8

[0.35, 1.44]

4.2

[2.22, 8.65]

0.0197