[Unusual presentation of rib malformation]

Area of Science:

• Anatomy
• Radiology
• Pediatrics

Background:

• Rib malformations and anatomical variations are often underdiagnosed and incidentally discovered.
• Anterior ribcage masses require careful evaluation to rule out serious pathologies.

Observation:

• A 4-year-old girl presented with fever and an anterior ribcage tumefaction.
• Ultrasound revealed a duplicated, hypoechogenic hypertrophy of the sterno-costal cartilage of the 4th left rib.
• Magnetic resonance imaging (MRI) confirmed chondral bifidity at the sterno-costal junction.

Findings:

• The patient's fever resolved with treatment for viral tonsillitis.
• Chondral bifidity of the 4th left rib was diagnosed.
• Rib malformations are typically anterior, unilateral, and involve the 3rd or 4th rib.

Implications:

• Accurate diagnosis of rib malformations is essential for appropriate management.
• Imaging, particularly MRI, plays a key role in differentiating benign rib anomalies from tumors like Ewing sarcoma.
• Understanding the topography of rib lesions aids in etiological diagnosis.