Respiratory bronchiolitis-associated interstitial lung disease - an unexpected form of idiopathic interstitial pneumonia in a young male

Abstract

Cigarette smoking is the most frequently encountered risk factor for chronic obstructive pulmonary disease and lung cancer. The latest American Thoracic Society÷European Respiratory Society classification of idiopathic interstitial pneumonia includes two entities related to smoking habits: respiratory bronchiolitis-associated interstitial lung disease and desquamative interstitial pneumonia. The new approach to diagnosis is to combine pathological pattern with clinical and radiological data. Lung biopsy is no longer considered the "gold standard" for diagnosis, but as a part of the diagnosis, which shall be set only after the pulmonologist, radiologist and pathologist reviewed all clinical, imaging and pathological aspects. We report a case of a young male, who complained of respiratory symptoms, had normal volumes and flows on lung function tests, moderately reduced transfer factor for carbon monoxide and "ground glass" attenuation on high-resolution computed tomography. Because the patient had exposure to contact with parrots, hypersensitivity pneumonitis was considered, but the broncho-alveolar lavage was without lymphocytosis. Open lung biopsy confirmed the diagnosis of respiratory bronchiolitis-associated interstitial lung disease, a rarely described entity in the medical literature. The patient had a good clinical outcome after smoking cessation.