COMPARISON OF BUFFY COAT PREPARATION TO DIRECT METHOD FOR THE EVALUATION AND INTERPRETATION OF BONE-MARROW ASPIRATES

Bone marrow differential and French, American, British (FAB) classific ation of buffy coat preparation (BCP) was compared to direct method (D M) in 69 pediatric patients with various hematologic and oncologic dis orders. The marrow evaluation differed significantly in 12 of 69 patie nts (17.4%). The differential counts were discordant in 9 out of 69 pa tients (13%), and the FAB classifications were discordant in 3 out of 25 patients (12%) with acute lymphoblastic leukemia (ALL). Underestima tion ot the percent blasts occurred with buffy coat preparation in pat ients with acute non-lymphoblastic leukemia (ANLL). While buffy coat p reparations can facilitate morphologic evaluation in marrow malignanci es, significant errors can occur in determination of the differential count. Direct smear should be used in conjunction with buffy coat smea rs in the evaluation of bone marrow aspirates.