Vertebral rarefaction in acute lymphoblastic leukaemia.

A 16-year-old boy is reported in whom back pain, due to localised osteoporosis and partial collapse of a lumbar vertebra, drew attention to unsuspected acute lymphoblastic leukaemia. The patient responded promptly to induction therapy, his symptoms disappeared, and he is presently in the maintenance programme. The skeletal lesion continues to heal slowly. Attention is drawn to this unusual presentation of acute lymphoblastic leukaemia, and the importance of bone-marrow examination in the study of unexplained cases of osteoporosis is emphasised.