1. Table 17.1 Classification of acute
lymphoblastic leukaemia (ALL) according to
the World Health Organization (WHO)
classification (modified).
Precursor lymphoid neoplasms
B lymphoblastic leukaemia/lymphoma
B lymphoblastic leukaemia/lymphoma, NOS
B lymphoblastic leukaemia/lymphoma with
recurrent genetic abnormalities
B lymphoblastic leukaemia/lymphoma with t(9;
22)(q34; q11.2); BCR-ABL1
B lymphoblastic leukaemia/lymphoma with t(v;
11q23); MLL rearranged
B lymphoblastic leukaemia/lymphoma with t(12;
21)(p13; q22); TEL-AML1 (ETV6-RUNX1)
B lymphoblastic leukaemia/lymphoma with
hyperdiploidy
B lymphoblastic leukaemia/lymphoma with
hypodiploidy (hypodiploid ALL)
T lymphoblastic leukaemia/lymphoma
NOS, not otherwise specified.
Table 17.2 Specialized tests for acute
lymphoblastic leukaemia (ALL).
Cytochemistry
Myeloperoxidase −
Sudan black −
Non-specific esterase −
Periodic acid–Schiff + (coarse block
positivity in ALL)
Acid phosphatase + in T-ALL (Golgi
staining)
Immunoglobulin and
TCR genes
B-ALL: clonal
rearrangement of
immunoglobulin genes
T-ALL: clonal
rearrangement of TCR
genes
Chromosomes and
genetic analysis
(Table 17.1)
Immunological markers
(flow cytometry)
(Table 17.3)
B-ALL, B-cell acute lymphoblastic leukaemia; T-ALL, T-cell
acute lymphoblastic leukaemia; TCR, T-cell receptor.

2. Table 17.3 Immunological markers for
classification of acute lymphoblastic (ALL)
leukaemia.
ALL
Marker B T
B lineage
CD19 + −
cCD22 + −
cCD79a + −
CD10 + or − −
cIg + (pre-B) −
sIg − −
TdT + +
T lineage
CD7 − +
cCD3 − +
CD2 − +
TdT + +
c, Cytoplasmic; S, surface.
* B-ALL resembles precursor B-ALL immunologically but
has surface immunoglobulin (Ig) and is terminal deoxynu-cleotidyl
transferase negative (TdT−).
Table 17.4 Prognosis in acute lymphoblastic leukaemia (ALL).
Good Poor
WBC Low High (e.g. >50 × 109/L)
Sex Girls Boys
Immunophenotype B-ALL T-ALL (in children)
Age Child Adult (or infant <1 year)
Cytogenetics Normal or hyperdiploidy;
TEL rearrangement
Ph+, 11q23 rearrangements
MLL gene rearrangement
Hypodiploidy (<44 chromosomes)
Time to clear blasts from blood <1 week >1 week
Time to remission <4 weeks >4 weeks
CNS disease at presentation Absent Present
Minimal residual disease Negative at 1 month
(children) or 3 months
(adults)
Still positive at 3–6 months
CNS, central nervous system; Ph+, Philadelphia chromosome positive; WBC, white blood cell count.