Table 2. Risk Factor Analysis of Pediatric PTC Patients Who Underwent Total Thyroidectomy, Comparing Unifocality and Multifocality.

Characteristics		Unifocality (n=42)	Multifocality (n=18)	p value	Univariate		Multivariate
					OR (95% CI)	p value	OR (95% CI)	p value
Age (yr)		15.8±1.9	14.7±3.4	0.245	0.84 (0.67–1.06)	0.149
Female sex		34 (82.9)	13 (76.5)	0.715	0.67 (0.17–2.67)	0.570
Primary tumor size (cm)		2.5±1.3	3.7±2.1	0.010	1.61 (1.08–2.40)	0.018	1.46 (0.74–2.88)	0.281
Primary tumor size >2 cm		22 (53.7)	11 (64.7)	0.564	1.58 (0.49–5.10)	0.441
Preoperative ultrasonography finding
	Solid parenchyma	35 (97.2)	12 (100)	0.999	N/A
	Calcifications	26 (72.2)	8 (66.7)	0.726	0.77 (0.19–3.13)	0.714
	Irregular margins	16 (44.4)	7 (58.3)	0.511	1.75 (0.47–6.57)	0.407
	Taller than wide	2 (5.6)	1 (8.3)	0.999	1.55 (0.13–18.73)	0.732
	Hypoechoic	28 (77.8)	8 (66.7)	0.462	0.57 (0.14–2.40)	0.445
	Ipsilateral nodule present	8 (22.2)	4 (33.3)	0.462	1.75 (0.42–7.35)	0.445
	Contralateral nodule present	13 (36.1)	5 (41.7)	0.743	1.26 (0.33–4.80)	0.731
Final pathology*
	PTC, classical	26 (63.4)	8 (47.1)	0.380	0.51 (0.16–1.61)	0.253
	PTC, diffuse sclerosing	6 (14.6)	3 (17.6)	0.999	1.25 (0.27–5.70)	0.773
	PTC, tall cell	4 (9.8)	3 (17.6)	0.407	1.98 (0.39–9.99)	0.407
	PTC, clear cell	2 (4.9)	2 (11.8)	0.573	2.60 (0.34–20.17)	0.361
	PTC, follicular variant	1 (2.4)	1 (5.9)	0.504	2.50 (0.15–42.44)	0.526
Bilaterality		9 (22.0)	8 (47.1)	0.067	3.16 (0.95–10.55)	0.061
Gross ETE		5 (12.2)	7 (41.2)	0.028	5.04 (1.31–19.34)	0.018	11.70 (0.56–44.95)	0.113
Number of central LN metastasis		6.4±5.7	10.2±5.7	0.025	1.09 (0.99–1.21)	0.076
Number of lateral LN metastasis		13.2±8.7	17.3±8.8	0.265	1.16 (1.01–1.32)	0.030	1.14 (0.95–1.36)	0.163

OR, odds ratio; CI, confidence interval; PTC, papillary thyroid cancer; ETE, extrathyroidal extension; LN, lymph node.

Data are presented as mean±standard deviation or n (%).

^*PTC, others were not included since no patient had multifocal disease.