Epidermoid Cyst vs. Meningocele
Left Picture: The diagnosis is an epidermoid cyst. Right Picture: The diagnosis is a meningocele. The reliability of both diagnoses can be increased by additional examinations such as ultrasound, CT and/or MRI. The additional examinations are useful mainly to recognize a possible continuation of an epidermoid or dermoid cyst to the inside of the skull, or, in case of a meningocele, to differentiate it from a meningoencephalocele, and to diagnose combined anomalies, such as hydrocephalus and other malformations.
Both pathologies lie in the midline over the back of the head and are covered with normal skin. Left Picture: Although the presented pathology is the most frequently observed lesion on the skull, its location in the midline is not really helpful for the differential diagnosis. The mass is firm and rather rough on palpation. The overlying skin is normal. Right picture: The mass is soft and gets tight when the child cries (combined with an increased intracranial pressure). The overlying skin is thin and consists only of epidermis. Left picture: The presented pathology becomes obvious only in the course of infancy. Right picture: This type of mass is present in its entirety already at birth. The described characteristics allow a fair reliable diagnosis of both pathologies.