Table 2. Overall sensitivity, specificity, PPV and NPV of SN biopsy and in the different studied groups.

Measures	Overall	Palpable LN	Non-palpable LNs US diagnosis	1 or 2 suspicious LN on US	Single suspicious LN on US
Sensitivity	0.46	0.63	0.20	0.45	0.60
Specificity	0.58	0.33	0.83	0.70	0.75
PPV	0.45	0.56	0.50	0.63	0.60
NPV	0.50	0.40	0.56	0.54	0.75

PPV, positive predictive value; NPV, negative predictive value; SN, sentinel node; LN, lymph node; US, ultrasound.