Optical pathway gliomas. A review of four cases.

Optical pathway gliomas are exceedingly rare tumors seen primarily in the p ediatric age group, in which they contribute 0.5 to 4% of all intracranial tumors. They raise both diagnostic and therapeutic problems. Four cases, in three girls and one boy, seen between 1994 and 1997 at the Neurosurgery De partment of the Ibn Rochd Teaching Hospital, Casablanca, Morocco, were revi ewed retrospectively. Mean age was 6.5 years with a range of two to nine ye ars. At presentation all four patients had ophthalmological manifestations: two had blindness In both eyes accompanied with endocrine dysfunction and two had exophthalmos. Computed tomography of the head and orbit showed a tu mor in the orbital portion of the optic nerve in two cases, with extension to the chiasma in one, whereas in the other two cases a tumor was seen in t he hypothalamochiasmatic region, with hydrocephalus in one case. Surgical r emoval was complete in two cases and partial in the other two. One patient received radiation therapy. There were two postoperative deaths, one due to electrolyte disturbances and the other to cerebral edema. Magnetic resonan ce imaging has added considerably to the management of optical pathway glio mas, most notably those located in the chiasma. The treatment strategy vari es with the age of the patient, the site of the tumor, and the aggressivene ss of the lesions. Gliomas of the chiasma are associated with a higher risk of treatment failure and death.