Acute lymphocytic leukemia (ALL) is a clonal stem cell malignancy of excessive lymphoblast proliferation. It is now understood that ALL and lymphoblastic lymphoma are the same disease entities at the morphologic and immunophenotypic levels and classified as either B- and T-cell lymphoblastic leukemia/lymphoma (B-ALL and T-ALL). In the case of B-ALL, numerous reports have demonstrated that recurring genetic abnormalities are associated with sufficiently unique clinical, immunophenotypic, and/or prognostic features so that they can be considered as distinct entities. The most common rearrangements observed in B-ALL are the t(12;21) (p13;q22) rearrangement resulting in expression of the ETV6-RUNX1 fusion (TEL-AML1); the t(1;19) (q23;p13) translocation that results in expression of the TCF3 (E2A) fusion partner, (also known as TCF3) TFPT-PBX1 fusion (E2A-PBX); the t(9;22) (q34;q11.2) "Philadelphia" chromosome resulting in expression of the BCR-ABL1 fusion; and rearrangements of MLL (also known as KMT2A) at 11q23 to a diverse array of fusion partners. If none of these specific genetic abnormalities are found, the designation of "B lymphoblastic leukemia/lymphoma, not otherwise specified," is appropriate.
Category
Cancer
Brite
Human diseases in ICD-11 classification [BR:br08403]
02 Neoplasms
Neoplasms of haematopoietic or lymphoid tissues
Precursor lymphoid neoplasms
2A70 Precursor B-lymphoblastic neoplasms
H00001 B-cell acute lymphoblastic leukemia
Tumor markers [br08442.html]
H00001
Acute lymphocytic leukemia (ALL) is a clonal stem cell malignancy of excessive lymphoblast proliferation. It is now understood that ALL and lymphoblastic lymphoma are the same disease entities at the morphologic and immunophenotypic levels and classified as either B- and T-cell lymphoblastic leukemia/lymphoma (B-ALL and T-ALL). T-ALL comprises 15% of paediatric and 25% of adult ALL cases. T cell transformation is a multi-step process in which different genetic alterations cooperate to alter the normal mechanisms that control cell growth, proliferation, survival, and differentiation during thymocyte development. In this context, constitutive activation of NOTCH1 signaling is the most prominent oncogenic pathway in T cell transformation. In addition, T-ALLs characteristically show the translocation and aberrant expression of transcription factor oncogenes. These oncogenic transcription factors include T-cell leukaemia homeobox protein 1 (TLX1 also known as HOX11), TLX3 (HOX11L2), LYL1, TAL1 and MLL.
Category
Cancer
Brite
Human diseases in ICD-11 classification [BR:br08403]
02 Neoplasms
Neoplasms of haematopoietic or lymphoid tissues
Precursor lymphoid neoplasms
2A71 Precursor T-lymphoblastic neoplasms
H00002 T-cell acute lymphoblastic leukemia
Tumor markers [br08442.html]
H00002
