Table 1.

Backgrounds and preoperative evaluation of 13 patients with contralateral but not ipsilateral N1b.

Case number	Gender	Age	Tumor size (cm)	Tumor multicentricity	Benign nodules at contralateral side	Central node metastasis	N1b size (cm)
1	Female	26	3.0	No	No	No	0.7
2	Female	54	1.1	No	Yes	No	0.8
3	Male	55	3.3	No	No	Yes	1.5
4	Male	24	4.5	No	No	Yes	0.9
5	Female	46	1.6	Yes	No	Yes	1.9
6	Female	69	0.7	No	No	No	1.6
7	Male	53	1.4	Yes	No	No	2.2
8	Male	57	1.9	No	No	No	0.6
9	Male	45	2.0	No	No	No	1.0
10	Male	50	3.0	No	Yes	Yes	0.8
11	Female	60	0.8	Yes	Yes	No	1.6
12	Female	67	1.9	Yes	Yes	Yes	3.1
13	Male	71	0.9	No	No	No	1.9