Hypopyon--an early sign of leukaemic relapse.

A 5-year-old girl with ALL developed leukaemic hypopyon after 33 months of treatment. Bone marrow and CNS relapse developed 3 months later, which was successfully treated. Local radiotherapy did not prevent an ocular relapse 2 months later, and a second course of irradiation was successfully given. She developed a second bone marrow relapse and died about 9 months after hypopyon was first identified. It is postulated that hypopyon may be an early sign of leukaemic relapse.