Table 2 Definition of primary tumor (T)
T Category | Thickness | Ulceration status |
|---|---|---|
TX: primary tumor thickness cannot be assessed (e.g., fragmented biopsy) | Not applicable | Not applicable |
T0: no evidence of primary tumor (e.g., unknown primary or completely regressed primary melanoma) | Not applicable | Not applicable |
Tis (melanoma in situ) | Not applicable | Not applicable |
T1 | ≤1.0 mm | Unknown or unspecified |
T1a | <0.8 mm | Without ulceration |
T1b | <0.8 mm 0.8–1.0 mm | With ulceration With or without ulceration |
T2 | >1.0–2.0 mm | Unknown or unspecified |
T2a | >1.0–2.0 mm | Without ulceration |
T2b | >1.0–2.0 mm | With ulceration |
T3 | >2.0–4.0 mm | Unknown or unspecified |
T3a | >2.0–4.0 mm | Without ulceration |
T3b | >2.0–4.0 mm | With ulceration |
T4 | >4.0 mm | Unknown or unspecified |
T4a | >4.0 mm | Without ulceration |
T4b | >4.0 mm | With ulceration |
