T Lymphoblastic leukaemia/lymphoma
T lymphoblastic leukaemia/lymphoblastic lymphoma is a neoplasm of precursor cells (lymphoblasts) committed to the T-cell lineage, typically composed of small to medium-sized blast cells with scant cytoplasm
Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J, Vardiman JW (Eds.)
WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues
International Agency for Research on Cancer: Lyon 2008
> T acute lymphoblastic leukaemia/ALL
This term is used in cases which extensively involve bone marrow (BM) and blood. For many treatment protocols, a figure of >25% BM blasts is used as the threshold for defining leukaemia.
> T lymphoblastic lymphoma/LBL
The term lymphoma is used when the process is confined to a mass lesion with no or minimal evidence of peripheral blood (PB) and BM involvement.
If the patient presents with a mass lesion and lymphoblasts in the BM, the distinction between leukaemia and lymphoma is arbitrary.