Four cases are presented that illustrate a wide spectrum of ophthalmologic and systemic features of necrobiotic xanthogranuloma (NXG). Case 1 initially had signs of Cogan syndrome, and then developed chronic lymphocytic leukemia. Case 2, the first case of NXG to undergo autopsy, had progressive cicatricial lid retraction and corneal perforation. Case 3 had a more typical presentation of diplopia and blepharoptosis caused by orbital and periorbital infiltrative masses. Case 4 had nondeforming periocular skin lesions over a 6-year period. In all four cases, the diagnosis was made on the basis of characteristic histopathologic and laboratory findings. Although the cause of NXG is still obscure, in many cases it appears to be a forerunner of lymphoproliferative diseases.