Introductory Chapter: Diagnosis of Interstitial Lung Disease

Interstitial lung diseases are rare diffuse lung disease characterized by a specific clinical picture and radiological (imaging) and pathohistological findings. It is considered that these diseases represent about 15% of all respiratory diseases [1]. Diffuse changes of the lung parenchyma in each type of these diseases are characterized by various morphological patterns which are reflected by a different imaging finding and a specific clinical picture [2–4]. The clinical picture at an early stage of the disease is not specific, and it is hard to suspect interstitial lung disease. Symptoms of interstitial lung disease are dry cough, short breath, fever, and fatigue. A specific high resolution computed tomographyn (HR-CT) finding indicates an interstitial lung disease which is proven by biopsy. Transbronchial biopsy primarily excludes specific granulomatous lung diseases, primary malignancy and metastatic as well as eosinophilic pneumonia, alveolar proteinosis, and pulmonary histiocytosis. If a bioptized lung sample has nonspecific morphological pattern, it is necessary to perform an open lung biopsy or video-assisted thoracoscopic surgery (VATS). Open lung biopsy procedure requires a multidisciplinary approach that includes a chest surgeon. An agreement on taking large number of lung tissue samples characterized by change evolution increases the efficiency and accuracy of the diagnosis [5]. Integrated clinical and radiological data help the pathologist to establish an accurate diagnosis of the type of interstitial lung disease. Besides pulmonologist, radiologist, and pathologist, microbiologist and immunologist also participate in diagnostic procedure [2–4].