Orbital, middle cranial fossa, and pterygopalatine fossa yolk sac tumor in an infant.

A yolk sac tumor, also known as an endodermal sinus tumor, was diagnosed in a 15-month-old infant who presented with rapidly progressive right eye proptosis. Imaging of the orbits and brain revealed a mass in the right orbit, middle cranial fossa, and pterygopalatine fossa. A lateral orbitotomy was performed to take a biopsy specimen and to partially debulk the tumor secondary to signs of optic nerve compromise. The biopsy specimen revealed a yolk sac tumor, and the patient underwent systemic chemotherapeutic treatment. Because orbital endodermal sinus tumors have been infrequently reported, there are no firm prognostic or treatment guidelines. Our case demonstrates that early recognition, limited orbital debulking, and chemotherapy can have an excellent short-term outcome.