The Ultrastructure of Hybrid Acute Leukemia: A Study of 15 Cases

Abstract

The objective of this study was to investigate the ultrastructural characteristics of hybrid acute leukemia (HAL). Fifteen cases of HAL were studied by transmission electron microscopy (TEM), focusing on organelles and myeloperoxidase (MPO) reaction of leukemic cells. By TEM, 5 out 15 cases of HAL were consistent with immunophenotyping (3 cases of biphenotypic type, and 2 cases of biclonal type with granulocytes and lymphocytes); 2 cases were suspected as HAL. On other hand, 5 cases of HAL were assigned to ALL, and 2 cases were misinterpreted as M5a and 1 as M4b. Most of the blast cells of biphenotypic HAL showed lymphoid features, except some cases containing MPO positive granules in blasts, while a few cases exhibited monocytic or nonspecific features. TEM offers advantages in the diagnosis of biclonal type HAL and biphenotypic HAL positive for MPO. However, it is difficult to differentiate MPO-negative cases of biphenotypic HAL from ALL and a few cases may be misinterpreted as M5 by TEM.

Ostra białaczka o mieszanym fenotypie – jak rozpoznać, jak leczyć?

“…Chorobę tę począt-kowo nazwano ,,białaczką komórki pnia z możliwością różnicowania w kierunku komórki limfo-i mieloidalnej'', a następnie ostrą białaczką bifenotypową (biphenotypic acute leukemia; BAL) [4], określaną w literaturze również jako ostra białaczka mieszana (hybrid acute leukemia; HAL) [5], ostra białaczka mieszanoliniowa (acute mixed lineage leukaemia; AMLL) [6][7][8], ostra białaczka dwuliniowa (acute bilineal leukemia; ABLL) [9,10], ostra białaczka biklonalna (acute biclonal leukemia; ABL) [5], ostra białaczka niezidentyfikowana (acute ambiguous leukemia; AAL) [9][10][11], ostra białaczka z niezidentyfikowanej linii (acute leukemia of ambiguous lineage; ALAL) [12], a ostatnio -ostra białaczka o mieszanym fenotypie (mixed phenotype acute leukemia; MPAL) [13,14].…”