Congenital papulonodular eruption: presenting sign of congenital leukaemia cutis.

Congenital leukaemia (CL) is a rare malignancy that accounts for < 1% of cases of childhood leukaemias. Leukaemia cutis (LC) refers to cutaneous infiltration with leukaemic cells, and is seen in 30-50% of CL cases. It may precede, follow or occur simultaneously with leukaemia. If left untreated, the prognosis is usually poor, but early diagnosis and treatment may result in a favourable prognosis. We report a case of congenital leukaemia cutis with a progressive, violaceous papulonodular eruption (a 'blueberry muffin' rash), which had been noted at birth, as a presenting sign of acute myeloid leukaemia (AML), which on investigation was classified as AML, FAB M2 type with a t(8; 21)(p11;q22) chromosomal defect. The patient had a favourable response to AML chemotherapy.