A 48-year-old woman with invasive ductal carcinoma undergoes total mastectomy. Final pathology shows a 4.5 cm tumor with direct extension to the chest wall (ribs and intercostal muscles). There is no skin involvement. Three fixed, matted ipsilateral axillary lymph nodes are found. What is the correct T category of this tumor?
- A T4a ✓
- B T3
- C T4b
- D T4c
Correct answer: A. T4a
Explanation
T4a denotes tumor extension to the chest wall (ribs, serratus anterior, intercostal muscles), regardless of size. T4b is skin edema, ulceration, or satellite skin nodules. T4c is both T4a and T4b. T4d is inflammatory carcinoma. Direct chest wall invasion qualifies as T4a even without skin changes. This is standard AJCC 8th edition TNM staging.
Reference: AJCC Cancer Staging Manual, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.