Acute Lymphoid Leukemia (ALL)
ALL is a malignancy of lymphoblasts (precursor T or B cells). There are three morphologic subtypes:
- L1 blasts are small and uniform with scant cytoplasm and inconspicuous nucleoli.
- L2 blasts are larger and more heterogeneous with variable amounts of cytoplasm, larger nucleoli, and irregularly shaped nuclei.
- L3 blasts correspond to Burkitt’s lymphoma cells and are medium-sized uniform blasts with basophilic and often vacuolated cytoplasm and prominent nucleoli
The L1 and L2 cells are similar to those of lymphoblastic lymphoma. Because of replacement of normal bone marrow cells by blasts in acute leukemia (ALL or AML), normal blood cell production is decreased and anemia, thrombocytopenia, or neutropenia are usually present and would be fatal without treatment. Acute leukemia can occur in all age groups. In childhood, acute leukemia is usually ALL.
| 12p rearrangements | |
| +21 | |
| del(6)(q13-q27) | |
| del(9)(p21-p22) | |
| del(12)(p12) | approx breakpt. |
| hyperdiploidy > 48ct. | |
| i(9q) | |
| i(17q) | |
| dic(9;20)(p11-13;q11.2) | pre-B |
| t(1;7)(p32-34;q34) | T-lineage |
| t(1;11)(p32;q23) | L1 |
| t(1;14)(p32-34;q11.2) | |
| t(1;19)(q23;p13.3) | L1, pre-B |
| t(2;8)(p12;q24.1) | (variant of t(8;14)) |
| t(4;11)(q21;p15) | T-lineage |
| t(4;11)(q21;q23) | L1, L2 |
| t(7;9)(q34-36;q34) | |
| t(7;10)(q34-36;q24) | T-lineage |
| t(7;14)(p15;q32) | |
| t(8;14)(q24.1;q11.2) | T-lineage |
| t(8;14)(q24.1;q32) | |
| t(8;22)(q24.1;q11.2) | (variant of t(8;14)) |
| t(9;22)(q34;q11.2) | |
| t(10;11)(p13-14;q14-21) | |
| t(10;14)(q24;q11) | T-lineage |
| t(11;14)(p13-15;q11.2) | T-lineage |
| t(11;19)(q23;p13.3) | L1, L2 |
| t(12;17)(p13;q21) | early B-precursor |
| t(14;18)(q32;q21) | |
| t(14;22)(q32;q11) | variant of t(9;22) |