Bathrocephaly vs. Posterior Fossa Cyst
Left picture: According to the additional x-ray examination of another child which is shown in the figure at the bottom, the diagnosis is a bathrocephaly as a normal variant. It may occur on the back head, which is shown here at the top, as well as on the posterior vertex shown at the bottom. Right picture: Using additional CT in the picture at the bottom, the cause of the externally visible prominence is a congenital cyst of the right cerebellar hemisphere, e.g. a porencephalic or an arachnoid cyst, which has led to a bossing of the occiput.
Both 6-month-old infants exhibit an occipital bossing. Left picture: The bossing is symmetrical and in the midline. Right picture: The prominence is asymmetric and on the right side laterally to the midline. Notice the position of the auricles.