Chewing-induced visual impairment from a dumbbell dermoid cyst.

A 29-year-old woman presented with a 1-year history of blurred vision in her left eye while chewing. Examination revealed a rubbery mass with ill-defined borders in the superotemporal brow region. Imaging studies demonstrated a cystic lesion extending from the temporal fossa into the orbit through a bony defect in the lateral orbital wall, assuming a dumbbell configuration. Histopathology of the excised specimen confirmed the clinical diagnosis of a dermoid cyst of cutaneous origin. We believe that the patient's visual disturbance was caused by transient displacement of orbital contents by the dermoid cyst as it was compressed into the orbit during mastication. Dermoid cysts are frequently associated with bony defects, which may require preoperative imaging and may produce unexpected symptoms.