A comparison of peripheral blood and buffy coat smear examination for the prediction of bone marrow relapse of acute lymphoblastic leukaemia in childhood.

In an attempt to see if buffy coat smear examination might be an alternative to bone marrow aspiration for predicting relapse, 98 consecutive bone marrow aspirates from 96 children with acute lymphoblastic leukaemia were examined blind with buffy coat and peripheral blood from the same patients. The 28 bone marrow aspirates from children no longer on treatment were all normal, and routine aspirates would appear unjustified in these patients. Eight of the remaining marrows showed relapse, but only three were not predicted from the peripheral blood and buffy coat. In no case was buffy coat superior to peripheral blood in the detection of bone marrow relapse. Routine bone marrow aspirates are an inefficient way of diagnosing relapse in acute lymphoblastic leukaemia in childhood, despite their precision, and a prospective study is needed to determine their value.