The Implications of Musculoskeletal Manifestations in Acute Lymphoblastic Leukemia: A Decade's Experience from a Referral Center in Southern India.

Objective: Children with acute lymphoblastic leukemia (ALL) with musculoskeletal (MSK) manifestations may be misdiagnosed as juvenile idiopathic arthritis (JIA). The present study compared the baseline parameters and survival outcomes in patients with ALL with and without MSK symptoms.

Methods: A retrospective chart review of children aged < 18 years diagnosed with ALL was performed. Based on contemporary parameters, the patients were stratified into standard-risk (SR), intermediate-risk (IR), and high-risk (HR) groups. Clinical and laboratory features and survival outcomes were compared between ALL patients with and without MSK symptoms.

Results: Out of 255 participants, 67 (26%) had MSK manifestations; of these, 9 were pretreated for JIA with glucocorticoids/methotrexate. Patients with MSK manifestations had a longer median duration of symptoms before diagnosis (4 vs 2 weeks, P < 0.001), and a higher median platelet count (53 × 10⁹/L vs. 28 × 10⁹/L, P = 0.002). The 3-year event-free survival (EFS) for patients with MSK and without MSK manifestations were 84.4 ± 5.2% and 78.9 ± 3.4% (P = 0.900). All 9 pretreated patients received an IR/HR protocol (4 were SR if not for the pretreatment as JIA).

Conclusion: Patients with ALL with MSK manifestations have more preserved blood counts and a longer duration of symptoms before diagnosis. Pretreatment of children with ALL misdiagnosed as JIA with glucocorticoids/methotrexate can delay the diagnosis, confound the risk stratification, and upstage the risk group requiring administration of more toxic chemotherapy than necessary otherwise.