In a patient with acute leukemia, immunophenotype pattern is CD 19+ve, CD 10+ve, CD33+ve, CD 13+ve. He may probably have -
Ans. is 'a' i.e., Biphenotypic leukemia o The information provided in the question is -- Patient is having acute leukemia Immunophenotypic pattern of the cells. CD 19 +ve CD 10 +ve CD 33 +ve CD 13 +ve o You know CD l0+ve and CD 19+ve is immunophenotypic pattern for B cell lineage. CD 33 & CD 13 is associated with monocyte & Macrophages o So it is clear that the patient is having acute leukemia with immunophenotypic pattern of more than one cell lineage. o So, ALL(option b) and AML (option c & d).are ruled outas these will have blast cells of one lineage only. o Now we are left with biphenotypic leukemia. o According to recent WHO classification (2008) of biphenotypic leukemia, we cannot make the diagnosis of biphenotypic leukemia in this question ( see previous explanation). Recent WHO (2008) classification of biphenotypic leukemia. Myeloid lineage B lymphoid lineage B lymphoid Lineage (multiple antigens required MPO or moncytic differentiation (at least 2 of the following : NSE CD11c CD 14, CD64, lysozyme) Cytoplasmic CD3 or Surcace CD3 Strong CD19 with at least 1 of the following weekly expressed : CD79a cytoplasmic CD22, CD 10 or weak CD 19 with at least 2 of the following strongly expressed : CD79a, cytoplasmic CD22, CD10 o This recent classification was made in 2008 ( while this question came in 2004). Before 2008, the criteria for diagnosis of biphenotypic leukemia was EGIL criteria modified by WHO. EGIL criteria for biphenotypic leukemia modified by WHO Score B lineage T lineage Myeloid 2 cCD 79a cIgM cCD22 CD3 (c or Sm) Anti-TCR (oc(l or 13) MPO 1 CD1 CD2 CD117 CD10 CD5 CD13 CD20 CD8 CD33 CD10 CD65 0.5 TdT TdT CD14 CD24 CD7 CD15 CD1a CD64 By WHO modified EGIL criteria the total score required for myeloid or lymphoid lineage is 2 for each
Biphenotypic leukemia
ALL
AML- M2
AML-M0