Table 3. Incidence of Ultrastage-detected, Low-Volume Metastases in SLNs by Final Histologic Grade and Depth of Myometrial Invasion.

DMI	Grade 1	Grade 2	Grade 3	Total
No Invasion	MM 1 ITC 1 n = 165	MM 0 ITC 0 n = 39	MM 0 ITC 0 n = 38	2/242 = 0.8%
< 50% invasion	MM 2 ITC 4 n = 80	MM 0 ITC 4 n = 62	MM 0 ITC 6 n = 56	16/198 = 8.0%
≥ 50% invasion	MM 0 ITC 2 n = 16	MM 0 ITC 0 n = 15	MM 1 ITC 2 n = 37	5/68 = 7.4%
Total	10/261= 3.8%	4/116= 3.4%	9/131 = 6.9%	23/508 = 4.5%

MM: micrometastasis; ITC: isolated tumor cells; DMI: depth of myometrial invasion