[Diffuse interstitial pneumonia revealing Erdheim-Chester's disease]. / Pneumopathie interstitielle diffuse révélant une maladie d'Erdheim-Chester.

ABSTRACT

Erdheim-Chester's disease is a rare form of visceral xanthogranulomatosis. We report a case of a patient aged 50 presenting with a diffuse interstitial pneumonia which revealed Erdheim-Chester's disease with localisation in the bones, peri-aortic region and also with neurological involvement. The diffuse interstitial pneumonia which progressed chronically was characterised by a diffuse thickening of the septa with subpleural cysts and bilateral apical bullae with thickening of the pleura. Respiratory function tests showed a restrictive ventilatory defect with resting hypoxaemia which was aggravating by exercise. Broncho-alveolar lavage showed a lymphocytosis (26%) also with polymorpho neutrophils (11%). The pathological diagnosis was confirmed by transbronchial lung biopsy showing an excess of foamy histiocytes in the interstitium which are characteristic of the disease. The progress of this interstitial pneumonia is stabilised without immunosuppressive drugs.