T-acute lymphoblastic leukemia (T-ALL)

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T-acute lymphoblastic leukemia (T-ALL) are neoplasms of immature T-cell precursors or lymphoblasts. T-ALL is less common than B-acute lymphoblastic leukemia (B-ALL) and accounts for approximately 15% of all childhood acute lymphoblastic leukemia (ALL) cases. These neoplasms tend to occur in older adolescents, with a male predominance.

As stated in the current World Health Organization classification, T-lymphoblastic leukemia/lymphoma is a neoplasm of lymphoblasts committed to T-cell lineage involving bone marrow (BM), blood, or presenting as a tissue-based mass involving the thymus, lymph nodes, or extranodal sites.

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Immunophenotypic Subtypes of T-ALL/T-LBL

 

Subtype                                  Key Markers (Cytoplasmic CD3 With)

Pro–T-ALL (T-I)                                                CD7+

Pre–T-ALL (T-11)                   CD2+ and/or CD5+ and/or CD8+

Cortical T-ALL (T-III)                                       CD1a+

Mature T-ALL (T-IV)                            Surface CD3+ (CD1a–)

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T-ALL, T-acute lymphoblastic leukemia; T-LBL, T-lymphoblastic lymphoma.

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Immunophenotyping:

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Example: Cortical T-ALL

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Above figure shows case of Cortical T-ALL, which shows( blasts-red and lymphocytes blue) positivity for cCD3, CD7, CD1a, CD10 dim, CD5 dim and negative for CD34, CD3, CD2, CD8, CD4, CD19, CD10, CD13, MPO, cCD79a.

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Example: Pre T-ALL

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Above figure shows case of Pre T-ALL, which shows( blasts-red and lymphocytes blue) positivity for cCD3, CD7, CD10 dim, CD5, CD2 dim, CD34 dim and negative for CD1a, CD3, CD8, CD4, CD19, CD13, MPO, cCD79a, CD117.

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Reference:

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