NCIt definition : Stage IIIA includes: T1a/b-T2a, N1a or N2a, M0. T1a: Tumor measuring less than 0.8
mm in thickness. Ulceration status: Without ulceration. T1b: Tumor measuring less
than 0.8 mm in thickness with ulceration, or 0.8-1.0 mm with or without ulceration.
T2a: Tumor measuring more than 1.0 and equal to or less than 2.0 mm in thickness.
Ulceration status: Without ulceration. N1a: One clinically occult nodal metastasis
(i.e., detected by sentinel lymph node biopsy). Presence of in-transit, satellite,
and/or microsatellite metastases: No. N2a: Two or three clinically occult nodal metastases
(i.e., detected by sentinel lymph node biopsy). Presence of in-transit, satellite,
and/or microsatellite metastases: No. M0: No evidence of distant metastasis. LDH level
is not applicable. (AJCC 8th ed.);