Abstract

Acute promyelocytic leukemia (APML) is a rare disease, associated with abnormal promyelocytes in bone marrow and a severe bleeding tendency. The disease should be managed as a medical emergency, and no more so than in pregnancy, as many patients develop fatal hemorrhages during diagnostic evaluation. An intriguing hypothesis to induce differentiation of APML cells rather than cell death was considered in the 1970s; the subsequent use of all-trans retinoic acid (ATRA) resulted in just that, producing a 90–95% remission rate in those treated.

ATRA is a synthetic form of a retinol found naturally in small quantities in the body. It is vital to the growth, differentiation and development of normal tissues, and induces apoptosis in certain cells. First trimester fetal exposure to high dose retinol is teratogenic. Effects of later exposure are less certain – although a detrimental effect on placental function could reasonably be postulated.

We report the case of a 39-year-old multiparous woman, who presented at 25 weeks gestation with breathlessness, spontaneous bruising and epistaxis. Full blood count showed pancytopaenia, and bone marrow aspirate confirmed a diagnosis of APML. Following discussion she was immediately commenced on ATRA, with good effect, producing complete remission. Serial scans confirmed good fetal growth velocity. Labour was induced at 35 weeks, delivering a 2500g male infant vaginally. Post-partum chemotherapy was commenced and she remains in remission.

This case adds to the limited evidence base available and, in addition, supports the extended use of ATRA in women diagnosed at the limits of fetal viability.