Isolated lymph node T lymphoblastic transformation of chronic myeloid leukemia during interferon treatment

Isolated nodal T lymphoblastic transformation of chronic myeloid leukemia (CML) with the marrow still in chronic phase is rare. A case of CML treated by alpha-interferon developed this unusual complication. However, after successful treatment of the blastic transformation, the patient remained responsive to interferon and maintained a major cytogenetic response for over 2 years. This case illustrated a rare clinical progression of CML on interferon treatment to isolated nodal T lymphoblastic transformation. This unusual form of blastic transformation may have a better prognosis than other forms of blastic crisis.