Respiratory failure during induction chemotherapy for acute myelomonocytic leukaemia (FAB M4Eo) with ara-C and all-trans retinoic acid.

We report two cases of acute myeloid leukaemia FAB classification M4Eo with high white cell counts at presentation, who developed acute respiratory failure with pulmonary infiltrates on chest radiograph soon after commencing conventional cytotoxic chemotherapy plus all-trans retinoic acid (ATRA). We suggest that in patients with M4Eo ATRA should be used with caution, perhaps delaying its commencement until the white cell count is < 10 x 109/l.