## TNM Staging for Breast Cancer — T Classification **Key Point:** The T (tumor) component of TNM staging in breast cancer is based on the greatest dimension of the primary tumor. ### T Classification Breakdown | T Stage | Size Criterion | Definition | |---------|----------------|------------| | **T0** | — | No evidence of primary tumor | | **T1** | ≤ 2 cm | Tumor ≤ 2 cm in greatest dimension | | **T1a** | ≤ 0.5 cm | Microinvasive | | **T1b** | 0.5–1 cm | — | | **T1c** | 1–2 cm | — | | **T2** | > 2 to ≤ 5 cm | **Tumor > 2 cm but ≤ 5 cm** | | **T3** | > 5 cm | Tumor > 5 cm in greatest dimension | | **T4** | Any size | Tumor of any size WITH chest wall or skin involvement | **High-Yield:** T2 is the most common presentation in breast cancer and is defined by the 2–5 cm range. This is a frequently tested fact in NEET PG. **Clinical Pearl:** T4 tumors are considered locally advanced and include inflammatory breast cancer (T4d), regardless of actual tumor size. The presence of skin or chest wall involvement upgrades the T stage to T4. **Mnemonic:** **"2-5 is T2"** — Remember T2 as the 2 to 5 cm range; T1 ≤ 2 cm; T3 > 5 cm; T4 = any size + invasion. 
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.