Hydatid cyst: unusual cause of unilateral exophthalmos

Intraorbital hydatid cysts are encountered unusually on neurosurgical services. Recently, 3 patients with intraorbital hydatid cysts have been studied by the Neurosurgical Service of C. S. "La Paz." In two of them, a computed tomography (CT) scan was performed; we think that these are the first cases of this type to be studied with CT scans. In each case, the CT scan showed a circular mass with a density similar to that of the eye. Frequency, localization, symptomatology, and neuroradiological aspects of intraorbital hydatid cysts are described. The different surgical approaches also are discussed.