Trigonocephaly and arachnoid cysts are two different entities that may cause intracerebral pressure elevation: one by space occupying and the other by space restriction. The true incidence of association of trigonocephaly and sylvian arachnoid cyst is not known. We present a rare case of trigonocephaly associated with a sylvian arachnoid cyst in a patient that underwent forehead reconstruction and fenestration of the arachnoid cyst in the same operation.Case report
Investigation of an 11-month-old girl suffering from triangular appearance of the forehead since birth revealed metopic suture synostosis and type II sylvian arachnoid cyst. Neurological examination was normal. There were no seizure history and no other systemic malformation that could be a part of any syndromes associated with cranial synostosis. Forehead reconstruction with forehead advancement for trigonocephaly and fenestration of the arachnoid cyst to the basal cisterns were performed in the same operation. Satisfactory outcome was achieved.Conclusion
The coexistence of craniosynostosis and arachnoid cyst is rare. They can be treated surgically in a single session.