Diffuse Parenchymal Lung Disease Flashcards
What is the path feature differentiating UIP from other idiopathic interstitial pneumonias?
Temporal heterogeneity
Surgical lung biopsy is not needed to establish the diagnosis of UIP if HRCT shows characteristic findings (subpleural site, basal predominance, reticular abnormality, honeycombing, and absence of features inconsistent with UIP).
What are the known genetic associations with pulmonary fibrosis?
Mutations in hTERT and hTR are risk factors for pulmonary fibrosis underlying the inheritance in 8–15% of familial cases. In these families, IPF is inherited as an autosomal dominant trait with age- dependent penetrance.
Histologically, respiratory bronchiolitis–associated interstitial lung disease is indistinguishable from respiratory bronchiolitis. Respiratory bronchiolitis– associated interstitial lung disease is characterized by clinical evidence of interstitial lung disease (impairment shown on pulmonary function tests and x-rays) and the finding of respiratory bronchiolitis on lung biopsy.
Which ILDs are most commonly associated with smoking?
Respiratory bronchiolitis– associated interstitial lung disease
desquamative interstitial pneumonia
pulmonary Langerhans cell histiocytosis.
Smoking cessation is a critical component of therapy.
Pulmonary arterial hypertension develops in > 15% of patients with systemic sclerosis/ scleroderma. It can be an isolated complication or secondary to ILD. These patients have a high mortality rate. Elevated levels of endothelin-1 cause enhanced vasoconstriction, vascular endothelial cell proliferation, smooth muscle hypertrophy, and irreversible vascular remodeling in the lungs
LAM is associated with which gene mutations?
LAM is associated with tuberous sclerosis complex, which is a multisystem genetic disorder caused by mutation of the TSC1 or TSC2 gene.
Which cells are pathognomic of pulmonary Langerhans cell histiocytosis on bronchoalveolar lavage?
BAL showing > 5% CD1a- positive cells is virtually diagnostic of pulmonary Langerhans cell histiocytosis.
Angiotensin-converting enzyme is created by granulomas and can be elevated in any granulomatous disease. Granulomas also produce calcitriol, which can lead to hypercalcemia.
What are normal BAL CD4/CD8 ratios and those in patients with sarcoidosis?
CD4/CD8 ratio 1.5–2.0 = normal
CD4/CD8 ratio >3.5 = suggestive of sarcoidosis
How does the BAL CD4/CD8 ratio differ in HSP and sarcoidosis?
CD4/CD8 ratio 1.5–2.0 = normal
CD4/CD8 ratio >3.5 = suggestive of sarcoidosis
What exposures can mimic sarcoidosis?
Nearly identical clinical and pathologic features can be seen in berylliosis, so a detailed exposure history is key.
BERYLLIOSIS
What exposures can mimic sarcoidosis?
What causes acquired pulmonary alveolar proteinosis?
Antibodies against GM- CSF
What imaging pattern is strongly suggestive of pulmonary alveolar proteinosis?
Crazy paving pattern
Infections in PAP?
PAP MAN infections:
Pulmonary
Alveolar
Proteinosis
Mycobacteria
Aspergillus
Nocardia
Is tracheobronchopathia osteochondroplastica associated with amyloid disease?
No, tracheobronchial amyloid is its own disease entity but can present very similarly. Submucosal involvement (posterior wall) is seen only with tracheobronchial amyloid disease.
What are the causes of noninfectious cystic lung disease?
Lymphangioleiomyomatosis
lymphocytic interstitial pneumonia
Langerhans cell histiocytosis
Birt-Hogg- Dube
rare forms of malignancy
How is infectious pneumonia distinguished from lipoid pneumonia on imaging?
CT scan shows fewer Hounsfeld units compared with typical infectious consolidations.
Which interstitial lung disease resembles acute silicosis histologically and on imaging?
Secondary pulmonary alveolar proteinosis, which causes alveolar filling with proteinaceous material that consists mostly of phospholipids and surfactant, staining with periodic acid–Schiff reagent (silicoproteinosis). Other exposures with similar findings are aluminum, silica, titanium, cement, insulation, sawdust, paint, varnish, chlorine, nitrogen dioxide, and fertilizer.
Which autoimmune disease is associated with Caplan syndrome?
Rheumatoid arthritis.
Caplan syndrome is a nodular reaction that occurs in individuals exposed to coal dust who also have rheumatoid arthritis or who will have rheumatoid arthritis within the next 5–10 years. The nodules can vary in diameter (0.5–5.0 cm) and are usually multiple, bilateral, and peripherally located. They contain a necrotic center surrounded by lymphocytes and plasma cells and a very small amount of coal dust.
Which pneumoconiosis is associated with melanoptysis?
Coal workers’ pneumoconiosis.
Melanoptysis is the expectoration of black sputum containing carbonaceous particles. It occurs when a conglomerate of nodules cavitates and ruptures into the airway. Melanoptysis has also been reported with freebase cocaine smoking, malignant melanoma, and aspergilloma caused by Aspergillus niger, as well as in progressive massive fibrosis caused by silicosis.
Anthracosis is the accumulation of coal dust within the lungs. It is often asymptomatic and can be seen in people living in large urban areas where there is significant air pollution.
There is a multiplicative risk of lung cancer in patients who are exposed to asbestos and smoke cigarettes. The relative risk of cigarette smokers with asbestos exposure is nearly 60.
