• Bone Disease
• Oncology
• Rheumatology

Missing a malignancy is a significant concern for paediatricians. It potentially leads to delay in treatment and impacts negatively on the doctor–patient/family relationship. Acute lymphoblastic leukaemia (ALL) is the most common cancer in childhood affecting around 4 per 100 000 children per year. Brix et al1 present a retrospective cohort of 286 patients with ALL diagnosed over two decades at two centres in Denmark. They highlight the frequent presence of musculoskeletal (MSK) symptoms and signs among newly diagnosed children, in particular 18.5% with localised joint pain of whom half had objective signs of arthritis. Other studies also suggest that MSK, and particularly joint, involvement is relatively common in ALL at around 10%–20%. However, the probability of any given child presenting with MSK symptoms having ALL remains very low.2 Only 10 of 1254 patients newly referred to a Paediatric Rheumatology unit over a 10-year period had malignancy, of which 6 had ALL, representing 0.5%.2 Another study reported 29 patients ultimately diagnosed with malignancy (13 leukaemias) referred to two North American Paediatric Rheumatology clinics over a 14-year period with a combined average new referral rate of 600/year, giving a leukaemia rate approximately 0.2%.3 Key …