Definition. A localized defect in the bone of the skull resulting from abnormal embryological development. The defect is covered by normal skin. In some cases, skull x-rays have shown underlying lytic bone lesions which have closed before the age of one year. [ from HPO]

What does Calvarial mean?

: the portion of a skull including the braincase and excluding the lower jaw or lower jaw and facial portion.

What is the Calvarium of the brain?

The calvarium is the convexity of the skull and encases the brain parenchyma. It is composed of the frontal, parietal, and occipital bones, and the squamosal portion of the temporal bones.