A 52-year-old man from Mumbai presents with a pigmented lesion on his back that has been growing over 6 months. Dermoscopy shows asymmetry, irregular borders, and mixed colors. Excision biopsy confirms cutaneous melanoma with a Breslow thickness of 2.8 mm, 3 mitotic figures per mm², and no ulceration. Which of the following is NOT a component of the AJCC TNM staging system for cutaneous melanoma?

Explanation

## AJCC TNM Staging for Cutaneous Melanoma ### Primary Tumor (T) Staging Criteria **Key Point:** The AJCC 8th edition (2017) uses four main criteria for T staging of cutaneous melanoma: | Criterion | Details | |-----------|----------| | **Breslow thickness** | Measured in millimeters from granular layer to deepest tumor cell; most important prognostic factor | | **Ulceration** | Presence or absence; indicates worse prognosis | | **Mitotic rate** | Counted per mm² in the dermis; ≥1 mitosis/mm² worsens stage | | **Clark level** | Used only when Breslow thickness <0.8 mm and no ulceration | ### What Is NOT Included in T Staging **High-Yield:** Satellite lesions (separate tumor nodules within 2 cm of primary) and in-transit metastases (within 2 cm to 2 m) are classified as **N staging** (nodal/regional disease), NOT as part of T staging. They represent regional metastatic disease and are staged as N1b, N2b, or N3b depending on number and location. ### Clinical Pearl The 2017 AJCC revision removed Clark level from routine T staging (except for thin melanomas <0.8 mm without ulceration) and emphasized Breslow thickness, ulceration, and mitotic rate as the primary determinants of T stage. ### Mnemonic **BUMP for T staging:** **B**reslow thickness, **U**lceration, **M**itotic rate, **P**igmentation (not actually used — but the first three are core). --- **Reasoning:** Satellite lesions and in-transit metastases are components of the **N (nodal) staging**, not T staging. They indicate regional spread beyond the primary tumor and are classified separately in the AJCC system.