Bone Marrow Involvement in Burkitt's Lymphoma: Results of a Prospective Study

S ummary Eighty‐five previously untreated patients with Burkitt's lymphoma were studied prospectively for the development of generalized bone marrow involvement by tumour. Fourteen (16%) of the patients in this series manifested marrow tumour involvement at some time during the course of their disease and seven of these presented with this complication. Only 20% of the affected patients had a peripheral leukaemic picture with a high percentage of circulating tumour cells. The prognosis associated with this complication appeared to be slightly worse in patients developing this picture following initial therapy than in those presenting with it. Pretreatment bone marrow lymphocyte counts were found to be 50% higher in patients who later developed bone marrow tumour involvement than in those who remained free of this complication. The implications of these observations are discussed.