G AUCHER'S disease is a relatively un- common, but by no means rare, dis- ease. Much has been written about it in the medical literature in which the full spec- trum of manifestations are described, in- cluding frequent reference to changes in the lungs. The radiologic literature has stressed the classic bone changes, but only briefly described the lung changes. Inter- estingly, these limited references to pul- monary changes have dealt only with children. The purpose of this paper is to call at- tention to the changes seen in the lungs and to report 3 patients, including, for the first time, an adult. According to Fredrickson and Sloan2 the underlying abnormality in Gaucher's disease is a defect in the enzyme B-gluco- sidase. The deficient activity of this en- zyme leads to accumulation of glucosyl- ceramide in neticuboendothelial cells which become altered in appearance, the so-called Gaucher cells. These accumulate in and enlarge the organs of the neticuloendothelial system, particularly, the liver, spleen, and deep lymph nodes. These cells also ac- cumulate in the bones and lungs and alter both their structure and function. There are at least 2 populations of Gaucher's patients and possibly 3 or more. All forms have in common hepatospleno- megaly, Gaucher cells in the marrow, and elevated serum acid phosphatase. Type i (adult type) is characterized by an absence of central nervous system in- volvement. The onset may be in childhood and most have symptoms on signs before the age of 2. It is usually slowly progressive with major findings being hypensplenism, bone pain, and pathologic fractures. How- ever, they may die early due to hemorrhage or poor response to minor illnesses.