Superior oblique muscle palsy in a patient with orbital dermoid cyst.

We describe the clinical and radiologic findings and surgical outcome of an orbital dermoid cyst causing a superior oblique muscle palsy in a child. Superior oblique muscle palsy in childhood is most often congenital. Less common causes are trauma, vascular lesions, neoplasms, and infections.(1,2) The most common orbital lesions in children are dermoid and epidermoid cysts.(3-5) A dermoid cyst at the region of trochlea is suspected as the cause of superior oblique muscle palsy in our case. This unusual presentation of a dermoid cyst has not been reported previously.