Abstract
A 55-year-old man with mental retardation and calcaneal tendon thickening was referred for a suspected genetic disease. His serum cholestanol was elevated and genetic analysis of his blood cells for CYP27A1 revealed a homozygous missense mutation. We diagnosed him with cerebrotendinous xanthomatosis (CTX). Chest radiography revealed diffuse micronodular and reticular opacities. Histological findings obtained from the transbronchial lung biopsy revealed foamy macrophages and multinucleate giant cells with marked lipid crystal clefts. Although there are few reports of pulmonary lesions in CTX, we concluded from the radiological and histopathological findings that the pulmonary lesions were indeed caused by the CTX. The patient was treated with chenodeoxycholic acid. His neurological findings and calcaneal tendon thickening were unchanged; however, his serum cholestanol and radiological abnormalities of the chest decreased.