A3.

Ann-Arbor (Cotswolds revised) stage system

Stage I: Disease is present in only one group of lymph nodes (I), or in a single extranodal organ (IE)
Stage II: Disease is found in two or more groups of lymph nodes on the same side of the body with respect to the diaphragm (II). In addition, an extranodal organ may be involved (IIE)
Stage III: Disease is present in lymph node groups on both sides of the diaphragm (III), or occasionally with the involvement of an extranodal organ (IIIE). If the spleen or/and an extranodal organ is involved then the disease becomes stage III as well (IIIS or IIIES)
Stage IV: Disease is present in one or more extranodal organs diffusely and dissenminately, which could be with or without lymph node involvement
Group A: Patients have no systemic symptoms
Group B: Patients have systemic symptoms, including unexplained fever (>38 ℃ for 3 consecutive days or more), night sweets (7 consecutive days or more) or weight loss (10% or more of weight within 6 months)
E: Lymphoma involves the extranodal organs. When lymphoma involves single extranodal organ/tissue connected to lymph nodes or lymphatic tissue, it is recorded as each stage +E instead of stage IV (e.g. lymphoma infiltrates to the skin connected to lymph nodes of left neck, it is recorded as “IE”)
X: Large mass, tumor diameter >1/3 of the width of the thorax or maximum diameter of the fused tumor block >7.5 cm