Although an uncommon condition, xanthoma tuberosum gives such a striking clinical picture and can be diagnosed so readily that unless there are additional features that reflect something of its cause, clinical reports alone are now passé. Necropsy reports are rare, but of these a sufficient proportion has disclosed analogous internal changes to indicate that in the future search for these should be made. In the first of our cases only the tendo patellae was affected in addition to the skin; but in our second case, the lungs, liver, skull, pineal body, pituitary and tuber cinereum were invaded, attaining, we believe, the high-water mark for extracutaneous xanthic involvement to date. Other features which threw sidelights on established or controversial phases of the disease were the association of xanthoma planum in Case 1, and of jaundice and hypercholesterolemia in Case 2. REPORT OF CASES Case 1.— Russell G., aged 36, white, who