NCIt definition : Stage IB includes: T2, N0, M0, B0,1. T2: Patches, papules, or plaques covering 10%
or more of the skin surface. N0: No clinically abnormal peripheral lymph nodes; biopsy
not required. M0: No visceral organ involvement. B0: Absence of significant blood
involvement: 5% or less of peripheral blood lymphocytes are atypical (Sezary cells).
B1: Low blood tumor burden: more than 5% of peripheral blood lymphocytes are atypical
(Sezary cells) but does not meet the criteria of B2. (AJCC 8th ed.);