Radiographic manifestations of congenital anomalies of the skull.

Congenital anomalies of the pediatric skull are caused by a diverse group of disorders. For the purposes of this discussion, these entities can be classified according to the radiographic appearance of the skull, which may be similar in a variety of different diseases. Enlarged parietal foramina, sinus pericranii, aplasia cutis congenita, anterior fontanelle dermoid, cephaloceles, and craniolacunia are all examples of loceles, and craniolacunia are all examples of calvarial defects. Although there are numerous causes for wormian bones (Table 1), OI, cleidocranial dysplasia, congenital hypothyroidism, and hypophosphatasia are disorders that are commonly associated with defective ossification and the appearance of wormian bones. Osteopetrosis is an important example of rare bony dysplasias that cause sclerosis and hyperostosis of the skull. A partial list of other disorders causing similar radiographic findings is found in Table 2. Craniosynostosis results in an abnormality of skull shape. The suture(s) involved may be predicted by the deformed calvarial configuration. Knowledge of the growth and development of the skull and an understanding of the varied causes of congenital skull anomalies can enable the radiologist to provide the diagnosis or an informed differential diagnosis when confronted with a specific radiographic finding.