Solitary metastatic tumor within the optic chiasm--case report.

A 61-year-old female, previously treated for lung cancer, presented with a rare case of metastasis directly to the optic chiasm manifesting as visual deficits. Magnetic resonance imaging revealed a suprasellar mass similar to an optic glioma. At surgery, the optic chiasm appeared swollen with hypervascularity over the surface. The bilateral optic nerves and the pituitary stalk appeared normal. A small incision was made on the superior surface of the chiasm and biopsy specimens were taken. The histological diagnosis was adenocarcinoma, which was consistent with the primary lung cancer. She received whole brain irradiation, resulting in mild improvement of her vision. Suprasellar metastatic tumors to the pituitary gland, pituitary stalk, and hypothalamus are well documented, but solitary metastasis within the optic chiasm should be considered as one of several differential diagnoses of suprasellar tumors, in patients with or without a history of treated cancer.