Pneumocystis pneumonia can present with<unk> , as seen in the reticular markings on this AP chest x-ray. A chest X-ray demonstrating pulmonary fibrosis due to amiodarone Investigation is tailored towards the symptoms and signs. A proper and detailed history looking for the occupational exposures, and for signs of conditions listed above is the first and probably the most important part of the workup in patients with<unk> . Pulmonary function tests usually show a restrictive defect with decreased diffusion capacity (DLCO). A lung biopsy is required if the clinical history and imaging are not clearly suggestive of a specific diagnosis or malignancy cannot otherwise be ruled out. In cases where a lung biopsy is indicated, a trans-bronchial biopsy is usually unhelpful, and a surgical lung biopsy is often required. X-rays Chest radiography is usually the first test to detect<unk> s, but the chest radiograph can be normal in up to 10% of patients, especially early in the disease process. High resolution CT of the chest is the preferred modality, and differs from routine CT of the chest. Conventional (regular) CT chest examines 7–10 mm slices obtained at 10 mm intervals; high resolution CT examines 1–1.5 mm slices at 10 mm intervals using a high spatial frequency reconstruction algorithm. The HRCT therefore provides approximately 10 times more resolution than the conventional CT chest, allowing the HRCT to elicit details that cannot otherwise be visualized. Radiologic appearance alone however is not adequate and should be interpreted in the clinical context, keeping in mind the temporal profile of the disease process.<unk> s can be classified according to radiologic patterns. Pattern of opacities ;Consolidation Acute: Alveolar hemorrhage syndromes, acute eosinophilic pneumonia, acute interstitial pneumonia, cryptogenic organizing pneumonia Chronic: Chronic eosinophilic pneumonia, cryptogenic organizing pneumonia, lymphoproliferative disorders, pulmonary alveolar proteinosis, sarcoidosis ;Linear or reticular opacities Acute: Pulmonary edema Chronic: Idiopathic pulmonary fibrosis, connective tissue-associated<unk> s, asbestosis, sarcoidosis, hypersensitivity pneumonitis, drug-induced lung disease ;Small nodules Acute: Hypersensitivity pneumonitis Chronic: Hypersensitivity pneumonitis, sarcoidosis, silicosis, coal workers pneumoconiosis, respiratory bronchiolitis, alveolar microlithiasis ;Cystic airspaces Chronic: Pulmonary langerhans cell histiocytosis, pulmonary lymphangioleiomyomatosis, honeycomb lung caused by IPF or other diseases Ground glass opacities Acute: Alveolar hemorrhage syndromes, pulmonary edema, hypersensitivity pneumonitis, acute inhalational exposures, drug-induced lung diseases, acute interstitial pneumonia Chronic: Nonspecific interstitial pneumonia, respiratory bronchiolitis associated<unk> , desquamative interstitial pneumonia, drug-induced lung diseases, pulmonary alveolar proteinosis ;Thickened alveolar septa Acute: Pulmonary edema Chronic: Lymphangitic carcinomatosis, pulmonary alveolar proteinosis, sarcoidosis, pulmonary veno occlusive disease Distribution ;Upper lung predominance Pulmonary Langerhans cell histiocytosis, silicosis, coal workers pneumoconiosis, carmustine related pulmonary fibrosis, respiratory broncholitis associated with<unk> . ;Lower lung predominance Idiopathic pulmonary fibrosis, pulmonary fibrosis associated with connective tissue diseases, asbestosis, chronic aspiration ;Central predominance (perihilar) Sarcoidosis, berylliosis ;Peripheral predominance Idiopathic pulmonary fibrosis, chronic eosinophilic pneumonia, cryptogenic organizing pneumonia Associated findings ;Pleural effusion or thickening Pulmonary edema, connective tissue diseases, asbestosis, lymphangitic carcinomatosis, lymphoma, lymphangioleiomyomatosis, drug-induced lung diseases ;Lymphadenopathy Sarcoidosis, silicosis, berylliosis, lymphangitic carcinomatosis, lymphoma, lymphocytic interstitial pneumonia Genetic testing For some types of paediatric<unk> s and few forms adult<unk> s, genetic causes have been identified. These may be identified by blood tests. For a limited number of cases, this is a definite advantage, as a precise molecular diagnosis can be done; frequently then there is no need for a lung biopsy. Testing is available for<unk> s related to alveolar surfactant region Surfactant-Protein-B Deficiency (Mutations in SFTPB) Surfactant-Protein-C Deficiency (Mutations in SFTPC) ABCA3-Deficiency (Mutations in ABCA3) Brain Lung Thyroid Syndrome (Mutations in TTF1) Congenital Pulmonary Alveolar Proteinosis (Mutations in CSFR2A, CSFR2B) Diffuse developmental disorder Alveolar Capillary Dysplasia (Mutations in FoxF1) Idiopathic pulmonary fibrosis Mutations in telomerase reverse transcriptase (TERT) Mutations in telomerase RNA component (TERC) Mutations in the regulator of telomere elongation helicase 1 (RTEL1) Mutations in poly(A)-specific ribonuclease (PARN)
Interstitial lung disease
Idiopathic pulmonary fibrosis
Alveolar lung disease
Alcoholic lung disease
Pulmonary interstitial emphysema
Pulmonary alveolar proteinosis
Pulmonary fibrosis
Emphysema