Denouement and Discussion
Congenital Subgaleal Cyst Over the Anterior Fontanel
Manifestations
The lesion presents as a cystic swelling over the anterior fontanel, usually at birth or by the first few months of life. The cysts are mobile, become firmer with crying, transilluminate, and are occasionally pulsatile. The smaller cysts have a clear, colorless fluid low in protein and glucose, while the larger ones have yellowish fluid with high protein and glucose levels. Also present in the cysts are desquamated epithelial cells, sebaceous material, and sometimes hair. Sweat glands, hair follicles, and sebaceous glands are also present in the wall of the cyst. On histological examination, the lesion consists of a dermoid cyst lined by attenuated stratified squamous epithelium. Infection of the cyst occasionally occurs.Roentgenograms of the skull show only soft tissue swelling. On air cystography, at which time the cyst is aspirated and air injected to replace the fluid,