ABSTRACT
The size and shape of the vault of the skull are determined by growth of the brain. The commonest abnormality of the cranium is hydrocephalus, which is caused by congenital abnormalities of the cerebrospinal fluid (CSF) pathway or by acquired obstruction of the CSF flow from haemorrhage, infection or tumour. Hydrocephalus is confirmed by observing an enlarged head circumference relative to that expected on a standard growth chart. Spina bifida with Arnold-Chiari malformation was once the commonest cause of hydrocephalus, but now intracranial haemorrhage in very premature babies is seen more frequently. Lymphatic malformations involving the neck or side of the face may present as non-tender swellings at birth. In the absence of haemorrhage into the cysts, they transilluminate. They may enlarge rapidly from both infection and haemorrhage. Reactive hyperplasia of the lateral cervical lymph nodes is by far the most frequent cause of a lump in the side of the neck.
