B-Cell Neoplasms |
Precursor B-Cell Neoplasms |
B-Lymphoblastic leukemia/lymphoma not otherwise specified (NOS) (Chap. 55) | Medium to large cells with finely stippled chromatin and scant cytoplasm | TdT+, sIg−, CD10+, CD13+/−, CD19+, CD20−, CD22+, CD24+, CD34+/−, CD33+/−, CD45+/−, CD79a+, PAX5+ | Clonal DJ rearrangement of IGH gene t(17;19), E2A-HLF, AML1 iAMP21 associated with poor prognosis |
B-Lymphoblastic leukemia/lymphoma with recurrent genetic abnormalities (Chap. 55) | See above | See individual features in subtypes below | See individual genetic features in B-ALL subtypes below |
B-ALL with t(9;22)(q34.1;q11.2); BCR-ABL1 | See above | CD19+, CD10+, TdT+, frequent expression of CD13 and CD33 | p190 BCR-ABL1 fusion present in most childhood cases; in about 50% of adult cases, p210 fusion present instead |
B-ALL with t(v;11q23); MLL rearranged | See above | CD19+, CD10−, CD24−, CD15+ | Multiple MLL (11q23) fusion partners including AF4 (4q21), AF9 (9p22), and ENL (19p13). B-ALL with MLL translocations overexpress FLT3. Poor prognosis |
B-ALL with t(12;21)(p13;q22); TEL-AML1 (ETV6- RUNX1) | See above | CD19+, CD10+, CD34+. Characteristically negative for CD9, CD20, and CD66c | t(12;21)(p13;q22) ETV6-RUNX translocation |
B-ALL with hyperdiploidy | See above | CD19+, CD10+, CD45−, CD34+ | Numerical increase in chromosomes without structural abnormalities. Most frequent chromosomes +21, X, 14, and 4. +1, 2, 3 rarely seen. Favorable prognosis |
B-ALL with hypodiploidy | See above | See above | Loss of at least one or more chromosomes (range from 45 chromosomes to near haploid). Rare chromosome abnormalities. Poor prognosis |
B-ALL with t(5;14)(q31;q32); IL3-IGH | See above with increase in reactive eosinophilia | See above. Even rare blasts with B-ALL immunophenotype with eosinophilia strongly suggestive of this subtype of B-ALL | t(5;14)(q31;q32); IL3-IGH leading to overexpression of IL3. Unclear prognosis |
B-ALL with t(1;19)(q23;p13.3); E2A-PBX1 | See above | CD10+, CD19+, cytoplasmic μ heavy chain. CD9+, CD34− | t(1;19)(q23;p13.3); leads to overexpression of E2A-PBX1 fusion gene product interfering with normal transcription factor activity of E2A and PBX1 |
Mature B-Cell Neoplasms | | | |
Leukemias | | | |
Chronic lymphocytic leukemia/ small lymphocytic lymphoma ... |