Table 1. The statistical difference between benign and malignant tumours concerning the qualitative variables.

Technique	Variable	Classification	Benign tumours	Malignant tumours	χ2	P-value
GSS	Borders	Ill defined	5 (17.9%)	14 (87.5%)	11.73	0.001*
		Well defined	23 (82.1%)	2 (12.5%)
	Homogeneity	Homogeneous	16 (57.2%)	8 (50%)	0.153	0.696
		Inhomogeneous	12 (42.8%)	8 (50%)
	Shape	Regular	7 (25%)	6 (37.5%)	4.086	0.130
		Irregular	12 (42.8%)	10 (62.5%)
		Lobulated	9 (32.2%)	0 (0%)
	Lymphadenitis	Present	5 (17.9%)	14 (87.5%)	11.73	0.001*
		Absent	23 (82.1%)	2 (12.5%)
CDS	Vascularity degree	Grade 0	2 (7.1%)	0 (0%)	9.35	0.025*
		Grade 1	21 (75%)	4 (25%)
		Grade 2	5 (17.9%)	10 (62.5%)
		Grade 3	0 (0%)	2 (12.5%)
	Vascularity distribution	Peripheral	17 (60.7%)	0 (0%)	10.476	0.005*
		Peri-lesional	2 (7.1%)	0 (0%)
		Scattered	9 (32.2%)	16 (100%)

P > 0.05 not significant; *P ≤ 0.05 significant; GSS, greyscale sonography; CDS, colour Doppler sonography