Some acute leukemias show both lymphoid and myeloid markers. These are termed biphenotypic acute leukemias (BAL). A scoring system developed by the European Group for Immunological Classification of Leukemias can be used to identify these tumors.
Marker groups:
(1) lymphoid, B-cell
(2) lymphoid, T-cell
(3) myeloid
|
B Cell Lymphoid Markers |
Points if Positive |
|
CD79a |
2 |
|
cyt IgM |
2 |
|
cyt CD22 |
2 |
|
CD19 |
1 |
|
CD10 |
1 |
|
CD20 |
1 |
|
Tdt |
0.5 |
|
CD24 |
0.5 |
|
T Cell Lymphoid Markers |
Points if Positive |
|
CD3 |
2 |
|
anti-TCR alpha/beta |
2 |
|
anti-TCR gamma/delta |
2 |
|
CD2 |
1 |
|
CD5 |
1 |
|
CD8 |
1 |
|
CD10 |
1 |
|
Tdt |
0.5 |
|
CD7 |
0.5 |
|
CD1a |
0.5 |
|
Myeloid Markers |
Points if Positive |
|
anti-MPO (anti-lysozyme) |
2 |
|
CD13 |
1 |
|
CD33 |
1 |
|
CDw65 |
1 |
|
CD14 |
0.5 |
|
CD15 |
0.5 |
|
CD64 |
0.5 |
|
CD117 |
0.5 |
total score for B lineage markers =
= SUM(points for all 8 markers)
total score for T lineage markers =
= SUM(points for all 10 markers)
total score for myeloid markers =
= SUM(points for all 8 myeloid markers)
Interpretation: An acute leukemia is defined as biphenotypic if either:
(1) score for myeloid markers > 2 and score for B lineage markers > 2
(2) score for myeloid markers > 2 and score for T lineage markers > 2
Specialty: Hematology Oncology, Clinical Laboratory
ICD-10: ,
