Ten stage I/II breast cancer patients with one or two suspicious lymph nodes (LNs) detected on ultrasonography underwent sentinel LN biopsy (SLNB) after the introduction of Twirl® breast markers into each suspicious LN revealed that each Twirl®-marked LN was SLN and was likely the first SLN. Three patients had less than three SLN metastases and were candidates for sparing completion axillary lymph node dissection (cALND). Indeed, of them, one underwent breast-conserving surgery without cALND and the other two underwent total mastectomy with cALND. These results suggest that, as all suspicious LNs are SLNs, patients can be treated with SLNB alone if they fulfill the ACOSOG Z-0011 criteria, despite suspicious LNs yielding positive results on preoperative fine-needle aspiration cytology.