Acute Hematogenous Osteomyelitis Presenting as a "Cold" Rib in a Child.

Area of Science:

• Pediatric infectious diseases
• Nuclear medicine imaging
• Skeletal infections

Background:

• Acute hematogenous osteomyelitis (AHO) is typically diagnosed via bone scintigraphy showing increased radiotracer uptake.
• Group A beta-hemolytic Streptococcus (GABHS) is an uncommon cause of AHO, especially in flat bones.
• The "cold" defect pattern on bone scans for AHO is less frequently observed.

Observation:

• A pediatric case of AHO presented with an unusual "cold" defect on a technetium-99m-methylene diphosphonate (Tc99m-MDP) bone scan.
• The infection was localized to a rib and associated with GABHS bacteremia.
• Magnetic resonance imaging (MRI) provided correlation, and pathological examination confirmed the diagnosis after rib resection.

Findings:

• This case demonstrates GABHS as a cause of "cold" AHO in a pediatric rib.
• The Tc99m-MDP bone scan revealed a decreased radiotracer deposition, characteristic of a "cold" lesion.
• Diagnostic imaging and pathological findings confirmed the rare presentation of osteomyelitis.

Implications:

• Highlights the importance of considering "cold" defects in Tc99m-MDP bone scans for AHO diagnosis.
• Suggests GABHS should be considered in pediatric AHO, even with atypical imaging findings.
• Emphasizes the value of multimodal diagnostic approaches including MRI and pathology for complex cases.