RÉSUMÉ
Background: Dermoid cysts are rare and benign tumors originating from failure of the normal embryologic development. Congenital inclusion dermoid cysts are usually located over the anterior fontanel. Surgical treatment is curative and provides good aesthetic results. The authors present a rare case of congenital inclusion dermoid cyst over the posterior fontanel and discuss the location, differential diagnosis, treatment and prognosis of this unusual pathological entity. Case description: A two-year old boy presented with a lesion on the posterior aspect of the head which had dated since birth. Imaging studies revealed an extracranial lesion over the posterior fontanel without intracranial extension. Surgical removal was performed and the histopathological examination confirmed the diagnosis of a dermoid cyst. The patient was discharged free of any medical complications. Conclusion: Although congenital inclusion dermoid cysts are more common over the anterior fontanel, they can occur over the posterior fontanel as well. Surgical treatment is curative in both locations with favorable aesthetic results.