Wormian bone in the anterior fontanelle

Case contributed by Imran Ahmad Khan


Infant with reduced head circumference and prematurely closed anterior fontanelle came for assessment of craniosynostosis.

Patient Data

Age: 3 months
Gender: Female

CT scan of the head


All the cranial sutures including the metopic, coronal, sagittal and lambdoid sutures are still open with no evidence of craniosynostosis. 

A large wormian bone is noted within the anterior fontanelle. Multiple small wormian bones are noted within the lambdoid suture.  

Brain appears unremarkable.

Case Discussion

Wormian bones are abnormal bones found between the skull's sutures, usually about the lambdoid suture 1. Wormian bones in the fontanelle are uncommon, and when they occur, they are mostly seen in the posterior fontanelle 2. Wormian bones in the anterior fontanelle are rare 2,3.

In this case, the clinician felt the anterior fontanelle was prematurely closed and found the head circumference to be smaller for the age. The findings were concerning for craniosynostosis and the child was sent for evaluation by CT scan.

CT scan shows the sutures are still open, but a large wormian bone is seen replacing the anterior fontanelle. Smaller wormian bones are also noted in the lambdoid suture.

No associated anatomical anomalies are present in the child with no features of osteogenesis imperfecta or any skeletal dysplasia.

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