Chiasmal syndrome due to metastasis.

We examined three patients with a chiasmal syndrome due to metastasis and were able to find only two additional cases in the literature. The characteristic presentation consisted of progressive impairment of vision without headache or abnormal plain skull x-ray films in patients with weight loss or diabetes insipidus. In three of the five patients, the primary malignant neoplasm was occult when symptoms and signs of chiasmal dysfunction were seen. Four patients responded well to irradiation. The chiasm may be compromised by suprasellar extension of pituitary metastasis, by infiltration from an infundicular or hypothalamic metastasis, or by hematogenous spread of tumor.