The usefulness of the lukes‐collins classification in identifying subsets of diffuse histiocytic lymphoma responsive to chemotherapy

Twenty‐nine patients with Stage III and IV diffuse histiocytic lymphoma (DHL) were treated prospectively with cyclophosphamide, hydroxydaunorubicin, vincristine, prednisone and bleomycin (CHOP‐B) or hydroxydaunorubicin, cyclophosphamide, vincristine, methotrexate with leucovorine rescue and cytosine arabinoside (ACOMLA). Twenty‐six evaluable patients were reclassified blindly by the Lukes‐Collins classification with five large noncleaved follicular center cell (FCC), six large cleaved FCC, three large cell unclassified, seven B‐immunoblastic sarcoma and five T‐immunoblastic sarcoma patients identified. There was no significant survival advantage between the two combination chemotherapy programs. Survival of the immunoblastic sarcoma patients was inferior to that of the FCC lymphoma patients (P = 0.02). There were no significant survival differences between the large cleaved FCC and noncleaved FCC subtypes. Immunoblastic sarcomas, B‐ and T‐cell types, appear to be more resistant to standard combination chemotherapy programs and new approaches may warrant more aggressive therapy in future protocols. The large cell FCC lymphomas have an excellent prognosis.