Siebenmann1in 1908 described a rare clinical syndrome characterized by peculiar yellowish white plaques in the oral mucous membrane and associated with hypertrophic lesions of the skin. His histologic studies indicated that these plaques consisted chiefly of infiltrated hyaline material. Wiethe2in 1924 described a similar congenital condition, which he also considered to be due to a diffuse hyaline change. Urbach3was the first to report that the infiltrate in this unusual condition contained lipoid and that this lipoid material was of the phosphatide (lecithin) type. He suggested that the condition was essentially a metabolic disturbance, possibly due to diabetes, and gave it the name "lipoidosis cutis et mucosae." Urbach and Wiethe4collaborated in 1929 and reported 9 cases of this syndrome occurring in four families. In 1932 Urbach5described clinical, histologic and biochemical observations on a total of 14 cases. He pointed out that