Normal variant consistent with parietal foramina

Findings

On the ultrasound, there were 2 discrete bony defects in the skull, seen in the parietal regions bilaterally, that demonstrate sharp margins. These were each approximately 2 cm in diameter. The x-rays also demonstrate these same 2 round lesions.


Diagnosis: Normal variant consistent with parietal foramina


Key points

Parietal foramina are normal variants.
Normal parietal foramina transmit the emissary veins of Santorini (there can be a depression in the outer table at the vein's exit).
Defects are insignificant except in the differential diagnosis of bony defects (from surgical intervention or trauma).
These congenital defects have a characteristic location, but may vary in size.
These are often symmetric, although they can be asymmetric and irregular.