Acute promyelocytic leukaemia presenting as necrotising fasciitis of the perineum (Fournier gangrene).

We present a case of an unusual presentation of acute promyelocytic leukaemia (APML), which presented with Fournier gangrene (FG). A 38-year-old man presented with malaise, groin swelling, anal bleeding, fever and was found to have FG. Initial workup revealed pancytopaenia, borderline low fibrinogen, prolonged international normalized ratio (INR), which raised the suspicion for leukaemia. The peripheral blood differential revealed leucopaenia with absolute neutropaenia and a 5% abnormal promyelocytes but no blasts, suspicious for APML. Bone marrow biopsy was performed and fluorescence in situ hydridization (FISH), karyotype and PCR confirmed a t(15;17) translocation, establishing a diagnosis of APML. After 1 month of therapy for intermediate risk APML with All-trans retinoic acid (ATRA) and arsenic trioxide (ATO), repeat chromosomal analysis and repeat bone marrow biopsy revealed no evidence of residual APML. After the consolidation phase was started with ATRA and ATO regimen, the wound healed after 2 months and the patient achieved complete remission.