[Sinus pericranii; a congenital swelling on the scalp].

Background: Sinus pericranii is a rare congenital disorder of the skull. It involves a venous connection between the intracranial and extracranial venous systems caused by a defect at the level of a cranial sinus.

Case Description: We present the case of a 20-year-old woman with a soft compressible swelling on the back of her head from birth. MRI examination revealed sinus pericranii. The treatment consisted of coagulating the venous connection and closing the cranial malformation.

Conclusion: In a patient with soft-tissue swelling on the back of the head that has been present since birth, differential diagnostics should extend beyond epidermoid cysts alone and also include consideration of sinus pericranii. This is particularly important if the swelling is in the midline.