MALIGNANT exophthalmos1is a clinical entity distinct from exophthalmos as generally seen accompanying thyrotoxicosis. These conditions may be closely related etiologically2; yet the diverse clinical pictures they present and the difference in their management make it necessary that the clinician be acquainted with the diagnostic criteria of the disease and the surgeon be familiar with the underlying pathologic process on which the treatment is based. In this paper I shall enlarge on these facts and introduce a new surgical approach, which I have employed successfully. HISTORY Malignant exophthalmos was first seen and described by von Basedow3in 1840. Since this initial report, 216 cases have been reported in the literature. (Würdemann and Becker,4Lahey,5Moore,6Zimmerman,7Hirsch and Urbanek,8Naffziger and Jones,9Gasteiger,10(Footnotes continued on next page) King,11Semmes,12Andersson,13Merrill and Oaks,14Bothman,15Means,16Hertz,17Thomas and Woods,18Rosenbaum,19Stallard,21Lyle,22Kistner,23Ginsburg24McCravey and Mather,25Reiching and