[Niemann-Pick disease type B identified following an episode of bronchopneumonia].

Niemann Pick disease type B (NPD type B) is a rare autosomal recessive lipid storage disorder, characterized by a partial deficiency of sphingomyelinase. We report the case of an adult male patient affected by NPD type B and diagnosed at 39-years-of age. Pulmonary CT scan revealed a cranio-caudal gradient with nodular centrilobular ground glass opacities and thickening of the interlobular septa. Pathological examination of the bronchoalveolar lavage showed foamy alveolar macrophages and vacuolated bronchial epithelial cells on bronchial biopsy. Diagnostic confirmation was achieved by a decrease in cell lysosomal enzyme activity and by the presence of the homozygous DeltaR608 mutation in the acid sphingomyelinase gene (SMPD1).