Musculoskeletal manifestations in pediatric acute leukemia

In children, acute leukemia (AL) at presentation can mimic several orthopaedic pathologies, so that a variable delay of the correct diagnosis is often reported.

To define more clearly the clinical and radiological musculoskeletal manifestations of leukemia in children, 122 affected children referred from 1984 to 1999 to our Pediatric Onco-Hematologic Clinic were retrospectively reviewed. Average age at diagnosis was 6.6 years (from 7 months to 17 years). Seventy-three (60%) were boys and adolescent boys, 49 (40%) were girls and adolescent girls. One hundred two (83.6%) had acute lymphoblastic leukemia, 20 (16.4%) had acute myeloid leukemia. The mean follow-up was 8.2 years for the 104 survivors and 2.5 years for the 18 nonsurvivors. The chi2 test was used to perform the statistical analyses.

At presentation, complaints related to the musculoskeletal system were frequent (38.3%), including pain (34.4%), functional impairment (22.9%), limping (12.3%), swelling (10.6%), and joint effusion (5.7%). At presentation, 40.2% of children had at least 1 radiographic abnormality. In order, they were osteolysis (13.1%), metaphyseal bands (9.8%), osteopenia (9%), osteosclerosis (7.4%), permeative pattern (5.7%), pathological fractures (5.7%), periosteal reactions (4.1%), and mixed lysis-sclerosis lesions (2.5%). Different from previous reports, late radiographic lesions were uncommon (5.7%), probably because of milder newer medication protocols. They included avascular necrosis (3.3%), vertebral collapses (1.6%), and osteolysis (0.8%).

Both clinical and radiological changes had various and no uniform localization. Poor correlation was found between symptoms and radiological lesions. Survival rates in children with AL were 95.8% at 1 year, 89.6% at 3 years, 85.8% at 5 years, and 83.4% at 10 and at 13 years. Radiographic abnormalities (P = 0.400), type of leukemia (P = 0.291), sex (P = 0.245), and white blood cell count at presentation (P = 0.877) were not prognostic factors. The presence of multiple bone lesions did not affect the survival rate (P=0.632). As early diagnosis significantly decreases morbidity and mortality of AL, the orthopaedist should suspect AL in any child with unexplained persistent skeletal pain or radiographic alterations. Accurate history, general physical examination, and complete blood cell count tests should address the suspicion, which is confirmed by a peripheral and/or iliac crest bone marrow biopsy.