Epidermoid Cyst vs. Enzephalocele
Left picture: The diagnosis is an epidermoid cyst. Right picture: Here, the diagnosis is a small encephalocele with dysplastic tissue under the skin, and a small connection to the inside of the skull, as shown in the picture at the bottom. In general, small encephaloceles do not increase in size during growth. Left picture: By contrast, epidermoid cysts may already reach a considerable size during the first year of life by accumulation of secretion, as demonstrated in the figure at the bottom.
In both patients a rather small swelling is visible in the midline over the vertex, covered by normal skin. Age of the patient, the configuration of the mass, and the natural course of the pathology are useful means in the differential diagnosis. Left picture: The patient is a young infant; the mass is round like a ball. It is growing in the following months (picture at the bottom). Right picture: At the top of the mass a dent is visible; the girl is 8 years old.