Pulmonary nodules refer to round or irregular lesions with a diameter less than or equal to 75px in the lungs, which can be single or multiple, with clear or unclear boundaries. Pulmonary nodules with different densities have different malignant probabilities. Pulmonary nodules can be divided into three categories according to their density: solid nodules, partially solid nodules and ground-glass density nodules. At present, the cause of pulmonary sarcoidosis is still unknown. Possible causes that have been explored include infection, chemical factors and drugs, allergies, autoimmunity and genetic factors.
Clinically, pulmonary nodules can be seen in the following conditions:
1. Pulmonary tuberculosis
Pulmonary tuberculosis is an infectious disease caused by Mycobacterium tuberculosis infection. Its basic pathological changes are inflammatory exudation, hyperplasia and caseous necrosis. Lesions dominated by hyperplasia may appear as typical tuberculosis nodules with a diameter of approximately 0.1 mm, and caseous necrosis may appear in the middle of the nodules.
2. Lung cancer
Lung cancer is one of the common malignant tumors, which can be divided into primary and metastatic cancer. Single or multiple nodules of varying sizes can be seen in both lungs of lung cancer. The nodules can include solid nodules, partially solid nodules, and ground glass nodules.
3. Pulmonary aspergillosis
Invasive pulmonary aspergillosis is mostly localized granuloma or extensive suppurative pneumonia, accompanied by abscess formation. The lesions showed acute coagulative necrosis, accompanied by necrotizing vasculitis, thrombus, and bacterial emboli. Its characteristic imaging manifestations are multiple wedge-shaped shadows or cavities based on the pleura. In the early stage, it is the halo sign, that is, pulmonary nodules.
4. Other conditions
In addition to the above common conditions, occupational-related pulmonary sarcoidosis also includes silicosis and pneumoconiosis, and immune-related pulmonary nodules include Wei Gehner's granulomatosis and pulmonary alveolar proteinosis.
In short, due to the complex causes of pulmonary nodules, don’t panic when you find pulmonary nodules. If a single solid small nodule is found during physical examination, if there is little change after repeated examinations, the possibility of benign will be higher. However, it is still recommended to continue follow-up reexamination until the total follow-up time is 24 months. At the same time, try to conduct reexamination under the same CT scan conditions to avoid bias in the observation of nodule information due to different conditions. If you also have lung discomfort, it is recommended to go to a specialist in time to conduct relevant examinations to determine the cause.