Leukaemic relapse of anaplastic large cell lymphoma, ALK negative

Anaplastic large cell lymphoma (ALCL), ALK negative (ALK-) is an aggressive lymphoproliferative disorder of mature T lymphocytes characterised by hallmark cells, CD30 positivity and lacking ALK protein expression. ALCL, ALK- has to be differentiated from peripheral T-cell lymphoma-not otherwise specified and classical Hodgkin's lymphoma. ALK- anaplastic large cell leukaemia should be considered in a patient with a history of ALCL, ALK- presenting with new leukaemia. We report a rare presentation of relapsed ALCL, ALK- with leukaemia after autologous stem cell transplantation in a 57-year-old male. Leukaemia, either as primary presentation or secondary transformation confers worse prognosis in ALCL, ALK- with very few cases reported so far. Emergency resuscitation with leukapheresis and treatment of tumour lysis syndrome along with supportive care should be followed by combination chemotherapy. Brentuximab vedotin and stem cell transplantation are the backbone of treatment for relapsed/refractory disease.