From the Guidelines
Lung granulomas are most commonly associated with infections, autoimmune disorders, occupational exposures, and hypersensitivity pneumonitis, and their diagnosis and treatment should prioritize addressing the underlying cause to improve morbidity, mortality, and quality of life. The most common causes of lung granulomas include:
- Infections (particularly tuberculosis, histoplasmosis, coccidioidomycosis, and atypical mycobacteria) 1
- Autoimmune disorders (such as sarcoidosis, rheumatoid arthritis, and granulomatosis with polyangiitis) 1
- Occupational exposures (berylliosis, silicosis) 1
- Hypersensitivity pneumonitis 1 These granulomas develop when the immune system attempts to wall off substances it perceives as foreign but cannot eliminate, forming multinucleated giant cells and epithelioid cells that characterize granulomas. Symptoms vary depending on the underlying cause but may include cough, shortness of breath, chest pain, fatigue, and weight loss. Diagnosis typically involves imaging studies, blood tests, and sometimes lung biopsy, with treatment focusing on addressing the underlying cause, which may include antimicrobial therapy for infections, corticosteroids for inflammatory conditions, or removal of exposure triggers in occupational or hypersensitivity cases 1. It is essential to identify the underlying cause of lung granulomas to provide effective treatment and improve patient outcomes, as highlighted in the European Respiratory Journal's clinical practice guidelines on treatment of sarcoidosis 1.
From the Research
Causes of Lung Granuloma
- Infectious causes: mycobacteria and fungi 2, 3, 4, 5
- Noninfectious causes: sarcoidosis, hypersensitivity pneumonitis, and vasculitis 2, 3, 4, 5
- Other causes: berylliosis, necrotizing sarcoid granulomatosis, bronchocentric granulomatosis, aspirated, inhaled, and embolized foreign bodies, drug-induced granulomas, chronic granulomatous disease, common variable immunodeficiency, and granulomatous lesions associated with various types of cancer 5
Diseases Associated with Lung Granuloma
- Sarcoidosis: a condition characterized by the formation of granulomas in various organs, including the lungs 2, 3, 4, 5
- Hypersensitivity pneumonitis: a condition caused by an allergic reaction to inhaled substances, leading to the formation of granulomas in the lungs 2, 3, 4, 5
- Tuberculous and nontuberculous Mycobacterial infections: bacterial infections that can cause the formation of granulomas in the lungs 5
- Fungal infections: infections caused by fungi that can lead to the formation of granulomas in the lungs 3, 5
- Vasculitis: a condition characterized by inflammation of the blood vessels, which can lead to the formation of granulomas in the lungs 2, 3