T-cell large granular lymphocyte leukemia (T-cell LGL leukemia) is a lymphoproliferative malignancy that arises from the mature T-cell (CD3+) lineage. The disease is MONDO_0019469 (T-cell large granular lymphocyte leukemia). Also known as: LGLL, T gamma lymphoproliferative disorder, T-LGL, T-LGL leukaemia, T-LGL leukemia, T-cell LGL leukaemia, T-cell LGL leukemia, T-cell large gran. lymph. leuk..