From the Guidelines
Old granulomatous disease on a chest CT scan is typically an incidental finding that doesn't require treatment if there are no active symptoms, as it usually indicates past infection with organisms like tuberculosis, histoplasmosis, or other fungal infections that have since resolved. This condition is characterized by evidence of healed or inactive granulomas in the lungs, which appear as small nodules or calcified spots in the lung tissue on CT scans 1. The presence of these findings suggests that the body has successfully walled off the infection site with calcium deposits, a process that is indicative of healing.
According to the American College of Radiology, CT chest scans are the preferred initial imaging modality for evaluating diffuse lung disease, including old granulomatous disease, due to their high sensitivity and specificity for lung parenchymal changes 1. The use of CT scans with intravenous contrast is not typically recommended for initial imaging of diffuse lung disease, but may be useful in evaluating alternative diagnoses or conditions that involve the pleura, mediastinum, and pulmonary vessels 1.
It's essential to discuss these findings with your doctor to confirm that they are indeed old and inactive, rather than representing active disease, especially if you have symptoms like cough, fever, or weight loss. Your doctor may recommend follow-up imaging in some cases to ensure stability of these findings over time. The presence and extent of HRCT imaging features of diffuse lung disease, including old granulomatous disease, may also serve as important prognostic variables 1.
Key points to consider:
- Old granulomatous disease on a chest CT scan is usually a benign finding
- It typically indicates past infection with organisms like tuberculosis, histoplasmosis, or other fungal infections
- CT chest scans are the preferred initial imaging modality for evaluating diffuse lung disease
- Follow-up imaging may be recommended to ensure stability of these findings over time
- The presence and extent of HRCT imaging features of diffuse lung disease may serve as important prognostic variables 1.
From the Research
Definition of Old Granulomatous Disease on CT Chest
Old granulomatous disease on CT chest refers to the appearance of granulomas, which are clusters of immune cells, in the lungs. These granulomas can be caused by various factors, including infections, autoimmune disorders, and environmental exposures.
Imaging Features
The imaging features of old granulomatous disease on CT chest include:
- Areas of consolidation 2
- Pulmonary nodules in a random distribution 2
- Centrilobular nodules 2, 3
- Tree-in-bud opacities 2
- Areas of scarring and traction bronchiectasis 2
- Emphysematous changes 2
- Areas of decreased attenuation and vascularity associated with air trapping on expiratory CT 2
- Mediastinal and/or hilar lymphadenopathy 2, 3
- Pulmonary artery enlargement 2
- Pleural effusion 2, 3
Causes of Granulomatous Disease
The causes of granulomatous disease can be infectious or non-infectious. Infectious causes include:
- Mycobacterial infections 3, 4
- Fungal infections, such as histoplasmosis 3, 4 Non-infectious causes include:
- Sarcoidosis 4, 5
- Hypersensitivity pneumonitis 4, 5
- Vasculitis 4, 5
Diagnostic Approach
The diagnostic approach to granulomatous disease involves a combination of clinical evaluation, laboratory testing, pulmonary function testing, radiological imaging, and histopathological assessment 6. A multidisciplinary approach is important for a confident diagnosis, as granuloma alone is a nonspecific histopathological finding 6.