Propi ' Osis Caused by Lipoidosis * by Ahmad Bey

AMONG cases of proptosis, I have met with three in which the causative lesion proved to be a form of lipoid granulomatosis, also known as lipoidosis and xanthomatosis. Two of these cases will be presented in this paper; in the third (Handousa, 1949) the lesion was mainly manifested in the temporal bones simulating double mastoiditis. The term lipoidosis covers several clinically distinguishable entities of disease resulting from disturbed fat metabolism. Three main varieties are usually described: Gaucher's disease, Niemann-Pick's disease, and HandChristian-Schiiller disease. They have the common feature of storage -of lipoid material in large cells derived from the reticulo-endothelial system. These cells are histologically characteristic and sufficiently diagnostic of lipoidosis. The type of lipoid stored differs in each entity. Kerasin is the main lipoid in Gaucher's disease, phosphatide in Niemann-Pick's disease, and cholesterol and its esters in Hand-Christian-Schiiller disease. Proptosis caused by lipoidosis is very rare and is usually one of the manifestations which may occur early or late in Hand-Christian-Schuller disease. Granulomatous masses forming at the base of the skull in this disease commonly spread and invade the orbit, pressing on the pituitary body and neighbouring structures, thus giving rise to exophthalmos, diabetes insipidus, etc. (MacCormac, 1938). In the case previously published (Handousa, 1949) the lipoid infiltration was a generalized process in which the orbital involvement was late. The possibility of a localized process of lipoidosis in the soft tissues of the orbit without any skeletal, visceral, or skin manifestations is demonstrated by the two cases here presented.