Here we explain what the stages of non-Hodgkin's lymphoma mean. It is very important to note that lymphoma is unlike most solid cancers. The stage is less important to the overall prognosis. Most patients, especially those with low-grade disease are diagnosed with stage III or IV, yet their prognosis is often very good.
Stage I NHL means involvement of a single lymph node region (I) or localized involvement of a single extralymphatic organ or site (IE).
Stage II NHL means involvement of 2 or more lymph node regions on the same side of the diaphragm (II) or localized involvement of a single associated extralymphatic organ or site and its regional lymph nodes with or without other lymph node regions on the same side of the diaphragm (IIE). Note: The number of lymph node regions involved may be indicated by a subscript (e.g., II3).
Stage III NHL means involvement of lymph node regions on both sides of the diaphragm (III) that may also be accompanied by localized involvement of an extralymphatic organ or site (IIIE), by involvement of the spleen (IIIS), or both (IIIS+E).
Stage IV NHL means disseminated (multifocal) involvement of 1 or more extralymphatic sites with or without associated lymph node involvement or isolated extralymphatic organ involvement with distant (nonregional) nodal involvement.
The stage can be further sub classified into A and B categories. The designation "B" after the stage indicates those with with well defined typical symptoms. The designation "A" indicates those without such symptoms. The B symptoms are defined as:
The designation "E" is used when extranodal lymphoid malignancies arise in tissues separate from, but near, the major lymphatic aggregates. Stage IV refers to disease that is diffusely spread throughout an extranodal site, such as the liver. If pathologic proof of involvement of 1 or more extralymphatic sites has been documented, the symbol for the site of involvement, followed by a plus sign (+), is listed. Sites are identified by the following notation:
N = nodes
H = liver
L = lung
M = bone marrow
S = spleen
P = pleura
O = bone
D = skin