Stage III Involvement of lymph node regions on both sides of the diaphragm (Stage III) that may also be accompanied by localized involvement of an extralymphatic organ or site (IIIE), involvement of the spleen (IIIS) or both (IIIS+E).
Stage IV Widespread involvement of one or more extralymphatic sites, with or without associated lymph node involvement, or isolated extralymphatic organ involvement with distant lymph node involvement.
Each stage may be further sub-divided into A or B according to the presence or absence of general symptoms. "A" means the absence of "B" symptoms, which include any of: unexplained fevers over 38°C (100.4°F), drenching night sweats or the unexplained loss of more than 10 percent of body weight.