Lameness in a 20 months girl,is it always a synovitis of the hip?

Lameness or musculoskeletal pain is a frequent consultation in the infancy. Its etiology is diverse and frequently not severe. In some cases lameness can be the initial symptom of neoplasic processes. Caucasic woman aged 20 months who presented lameness of two weeks of evolution. In the initial evaluation in Health primary care center we didn't appreciate any severity process. An ultrasound scan of hips was realized and she was diagnosticated of transient sinovitis of the hip. After a period of relative rest and anti-inflammatory treatment medical staff didn't appreciate any improvement. Several weeks later she presented intermitent night pain in the legs. A blood sample was taken and discovered neutropaenia. Given the persistence of the lameness, night pain and neutropenia, paediatrician sent the patient to paediatric oncohematology department where the diagnosis of linfoblastic leukaemia was realized after bony marrow aspiration.