Updating The Who Classification

Previous experience, especially with the Working Formulation, has shown that lymphoma classification is necessarily a constantly moving target. New con-

Table 51.2 Relative incidence of non-Hodgkin's lymphomas (Non-Hodgkin's Lymphoma Classification Project)

Diffuse large B cell

30.6%

Follicular

22.1%

Marginal zone B-cell of MALT type

7.6%

Peripheral T cell

7.0%

Small B lymphocytic

6.7%

Mantle cell

6.0%

Primary mediastinal large B cell

2.4%

Others

17.6%

cepts and consequently newly recognized diseases are constantly arising and demand to be included in current classifications. The REAL classification recognized this both tacitly and overtly by the inclusion of provisional entities. The question of how to address the problem of updating the classification was left hanging, however. In this respect it was a fortunate coincidence that, shortly after the publication of the REAL classification, the WHO commenced the ambitious project with the aim of formulating a new comprehensive classification of both lymphoma and leukemia. In terms of the lymphomas, the WHO classification project has essentially addressed the immediate problem of updating and refining the REAL classification. However, the problem of continuous updating of the WHO classification still remains to be addressed.

0 0

Post a comment