When the bronchoalveolar lavage makes the diagnosis of interstitial pneumonia

Abstract

A 30-year-old non-smoker woman without a particular past medical history consulted for dyspnoea and non-productive cough. Chest CT scan revealed mediastinal and hilar adenopathies associated with bilateral ground glass opacities with thickened interlobular septa. Bronchoalveolar lavage was performed (Fig. 1). The fluid was opaque with a milky turbid gross appearance. On microscopic examination, finely granular amorphous material was apparent in the background along with numerous lymphocytes and fragmented macrophages. Zhiel stain was performed but was negative. The diagnosis of pulmonary alveolar proteinosis (PAP) was suspected but the association of mediastinal adenomegalies was not concordant with the diagnosis. Surgical biopsy of the lung and the mediastinal lymph nodes was performed. Histological examination revealed granulomatous inflammation with caseous necrosis in the lymph nodes and an amorphous PAS positif lipoprotein material filling the alveolar spaces in the lung (Fig. 2). The final diagnosis of associated PAP with tuberculosis infection was established. The patient was put on anti-tuberculosis drugs and presented an improvement of her general state.