Flow cytometric DNA analysis of malignant lymphomas with primary bone manifestation.

Malignant lymphomas with primary skeletal manifestation have received controversial evaluation with regard to histological classification and histogenesis. Recent histological and immunohistological studies on the rare bone lymphomas conducted by our team, have shown that they do not differ from primary nodal lymphomas with regard to the spectrum of histological subtypes. The present flow cytometric DNA analysis of paraffin-embedded material from 17 lymphomas documented in the Bone Tumor Registry of Westfalia yielded the following distribution pattern of DNA ploidy: among 12 non-Hodgkin's lymphomas (NHL) (according to the Kiel classification) there was only 1 case of low grade malignancy; this centroblastic-centrocytic lymphoma showed a unimodal diploid DNA histogram. Of 11 highly malignant NHL, 6 were DNA hyperdiploid. Among the 5 cases of Hodgkin's lymphoma, 4 were DNA diploid, (1 nodular sclerosing, 3 mixed types) and one DNA tetraploid (lymphocytic depletion type). Comparison with data from the literature reveals that even with regard to DNA ploidy, malignant lymphomas primarily manifesting in bone do not differ from those of exclusively nodal manifestation.