A rapid increase in the normal white cell counts without blasts as the initial presentation of T-cell acute lymphoblastic leukaemia.

A 5-year-old girl with multiple enlarged cervical lymph nodes consistent with Epstein-Barr virus infection showed a rapid increase in the white blood cell counts (myeloid cells and lymphocytes) without blasts over a week period. Bone marrow evaluation performed after a week's observation unexpectedly showed replacement of the marrow with T lymphoblasts. A presentation of T-cell acute lymphoblastic leukaemia (T-ALL) in this fashion is very unusual.