[Interstitial pneumopathy revealing type B Niemann Pick disease in an adult].

Introduction: Niemann-Pick disease is an autosomal recessive disorder due to partial or total deficit in sphingomyelinase.

Exegesis: We report a case of type B Niemann-Pick disease revealed by pneumonia and splenomegaly associated with blue histiocyte syndrome. Investigations that were done 2 years prior to diagnosis had shown the existence of isolated chronic lipid pneumonia which is specific of overloading.

Conclusion: Though diagnosis is based on biochemistry, the morphology of alveolar histiocytes after simple bronchoalveolar lavage is of value.