Extramedullary disease in acute promyelocytic leukaemia: A rare presentation

Acute promyelocytic leukaemia consists of 7%–8% of cases of acute myeloid leukaemia. Extramedullary manifestations are rare and show distinct biological features. We describe a 22-year-old female of Malay ethnicity who presented with fever and a left axillary swelling for a week. The peripheral blood smear showed abnormal promyelocytes with faggot cells. PML-RAR-alpha t(15;17) (q22; q12) was detected by polymerase chain reaction. The left axillary swelling histology and immunohistochemical staining confirmed granulocytic sarcoma. She was induced with triple agents consisting of all-trans-retinoic-acid, arsenic trioxide and idarubicin. On day 14 of induction, she developed severe neutropenic sepsis in which she responded to ventilation and antimicrobials. She completed her induction, consolidation and maintenance therapy. Currently she is in molecular and morphological remission. Extramedullary disease in acute promyelocytic leukaemia usually has a severe clinical presentation. Granulocytic sarcoma may present as an early feature of acute promyelocytic leukaemia.