Working Formulation for Non-Hodgkin Lymphoma
The Working Formulation was developed by the National Cancer Institute in 1982 as a method of translating among the recognized classification systems for non-Hodgkin lymphoma (Rappaport, Dorfman, Lukes and Collins, Kiel, and the British Lymphoma system). The major groups are identified by letters, A - J, and grouped according to prognosis:
|most favorable||Low Grade||A, B, C|
|Intermediate Grade||D, E, F, G|
|least favorable||High Grade||H, I, J|
|Low Grade||Intermediate Grade||High Grade|
|Small lymphocytic||Follicular large cell||Large cell immunoblastic|
|Follicular small-cleaved cell||Diffuse small cleaved cell||Lymphoblastic|
|Follicular mixed small-cleaved and large cell||Diffuse mixed small and large cell||Small non-cleaved cell (Burkitt and non-Burkitt type)|
|Diffuse large cell|
Cell types categorized as unclassified by the Working Formulation include the nonspecific terms malignant lymphoma, non-Hodgkin lymphoma, diffuse malignant lymphoma, nodular or follicular malignant lymphoma, and cutaneous lymphoma.
Differences in histology refer to differences in the first 3 digits of the ICD-O morphology code.
A simultaneous diagnosis of malignant lymphocytic lymphoma (small cell type) and chronic lymphocytic leukemia (CLL) is coded to CLL.