A reappraisal of routine marrow examination therapy of acute lymphoblasticv leukaemia.

Out of 557 routine marrow examinations performed in children receiving maintenance therapy, or having completed therapy, for acute lymphoblastic leukaemia or non-Hodgkin's lymphoma, only 9 marrow relapses were found. Out of 14 marrow examinations performed because of haematological or clinical indications of possible relapse, only 3 failed to confirm relapse. It is suggested that routine marrow examination to detect relapse is not worthwhile and should be stopped.