Periostitis as Initial Sign of Pediatric Acute Lymphoblastic LeukemiaOA

A 5-year-old girl presented with 15 days of insidious-onset pain in the lower legs(left>right)and mild forearm pain with gradual worsening.Examination showed normal limb bulk with tenderness along the lateral forearms and legs.Laboratory evaluation revealed leukocytosis(28,760/mm^(3)),elevated erythrocyte sedimentation rate(29 mm/h),and elevated C-reactive protein(24 mg/L).