A 45-year-old woman undergoes sentinel lymph node biopsy (SLNB) for a 1.8 cm Grade 2 IDC. The sentinel node shows a 0.4 mm isolated tumour cell cluster (ITC). According to current AJCC 8th edition staging, this node status is classified as:
- A pN0(i+) — not considered positive disease ✓
- B pN1mi — micrometastasis requiring axillary lymph node dissection
- C pN1a — macrometastasis requiring complete ALND
- D pN0 — completely node-negative
Correct answer: A. pN0(i+) — not considered positive disease
Explanation
ITCs are defined as single cells or small clusters ≤0.2 mm (or <200 cells per single cross-section). They are classified as pN0(i+) — indicating isolated tumour cells detected by immunohistochemistry but NOT considered a true lymph node positive finding for staging or treatment-decision purposes. Micrometastases (0.2–2 mm) are pN1mi, while macrometastases (>2 mm) are pN1a. The distinction is clinically significant as pN0(i+) generally does not trigger additional axillary surgery.
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.