Stage I-involvement of a single lymph node region or lymphoid structure or involvement of a single extralymphatic site (E)
Stage II-involvement of ≥ 2 lymph node regions on the same side of the diaphragm; localized contiguous involvement of only one extranodal organ or site and lymph node regions(s) on the same side of the diaphragm (IIE)
Stage III-involvement of lymph node regions on both sides of the diaphragm (III), which may also be accompanied by involvement of the spleen (IIIS) or by localized contiguous involvement of only one extranodal organ site (IIIE) or both (IIISE)
Stage IV-diffuse or disseminated involvement of ≥ 1 extranodal organs or tissue, without associated lymph node involvement.
B-Fever(>38′), drenching night sweats, unexplained weight loss of 10% of body weight within the receding 6 months.
E-involvement of a single extranodal site that is contiguous or proximal to the known nodal site.