Table 4. Analysis of the 42 discordant cases between OSNA and histology.

Number of SLNs	Size of metastasis	OSNA Results	OSNA Copies/µl	Molecular Subtype	ALND Results
Histology Results: negative
2	−	+	≥2500≤3200	HS	+
1	−	+	3600	LA	+
3	−	+	≥6300≤1700	HS	−
3	−	+	≥300≤540	LB	−
2	−	+	≥270≤830	TN	−
14	−	+	≥280≤1400	LA	−
3	−	++	≥8000≤21000	LA	+
Total 28
Histology Results: micrometastasis
7	0.1–1 mm	−	<250	LA	−
Histology Results: macrometastasis
2	2.5 mm	−	<250	LA	+
2	3.0 mm	−	<250	LA	−
3	2.5–3 mm	−	<250	HS	−
Total 14

OSNA: one step nucleic acid amplification; SLN: sentinel lymph node; HS: HER2 subtype; LA: Luminal A; LB: Luminal B; TN: Triple Negative; ALND: axillary lymph node dissection.