Summary

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. We postulate that the T-lymphoblasts may have been secreting granulocyte colony stimulating factor like substance. We are unable to find a similar case report in the literature, and thus we wish to report this case. The patient has been treated with Children's Oncology Group T-ALL protocol, and has been in continuous remission.