Comparative histology of malignant lymphomas in lymph node and bone marrow.

Lymph node and bone marrow biopsies of 226 patients with malignant lymphomas were available for evaluation and comparison. 120 of the 226 lymphoma patients had classifiable infiltration in both lymph node and bone marrow and these were used for comparison. Congruence in the histologic subtypes in lymph node and bone marrow was found in 91 patients (76%). The majority of the 29 cases with divergent histologies showed ML of low grade malignancy in the bone marrow even with long time intervals between the two biopsies. The most notable in this group were seven cases who had ML centroblastic/centrocytic in the lymph node biopsy and ML immunocytic in the bone marrow, although none had a serum M-component. 65 of the 106 patients excluded from comparison had involvement in only one organ, the others had unclassifiable or equivocal histologies in either lymph node or bone marrow or in both. The findings are discussed with respect to the histologic behaviour of the lymphomas. The results show that comparison between lymph node and bone marrow findings in patients with ML is feasible and clinically relevant.