A sentinel lymph node biopsy in a patient with clinically node-negative breast cancer reveals 2 sentinel nodes with isolated tumor cells (ITCs, <0.2 mm) detected only on IHC. According to current staging (AJCC 8th edition), the nodal stage is:
- A pN0(i-)
- B pN1mi
- C pN0(i+) ✓
- D pN1a
Correct answer: C. pN0(i+)
Explanation
Isolated tumor cells (ITCs) measure ≤0.2 mm or contain fewer than 200 cells and are detected by IHC or molecular methods; these are classified as pN0(i+), indicating node-negative disease with IHC-detected cells. Micrometastases (>0.2 mm but ≤2 mm) are pN1mi. Macrometastases (>2 mm) in 1-3 nodes are pN1a. The distinction matters for prognosis and trial eligibility but pN0(i+) does not mandate completion axillary dissection in most protocols.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.