Most 4mm ground glass nodules are the result of benign lung disease, such as pneumonia, and are often not serious; the likelihood of them being malignant is low, but they are more serious.
The malignancy rate of 4mm lung nodules is about 1%. Milled glass nodules can be categorized as pure milled glass nodules or mixed milled glass nodules; the risk of malignancy for pure milled glass nodules is low, about 18%, and the risk of malignancy for mixed milled glass nodules is high, about 63%. the overall risk of malignancy for small 4-mm milled glass nodules is not high.
If the 4mm ground-glass nodule is caused by pneumonia due to bacterial or viral infection, it is not serious and can be treated with ceftriaxone and other medications in a timely manner, and only a small number of patients with severe pneumonia have serious conditions. If it is focal fibrosis, it is mostly the fibrous foci left over by lung inflammation, and generally no special treatment is needed.
In case of small nodules caused by charcoal deposition, the foci are mostly confined and the condition is mild, which can be treated with sputum-cleansing drugs such as aminoglutethimide and regular review.
If it is caused by carcinoma in situ or atypical neoplastic hyperplasia, it is the precursor lesion of lung adenocarcinoma and has the risk of malignant transformation, but the condition is not very serious, so observation and follow-up are sufficient. If it is caused by bronchopulmonary cancer, it is more serious and can be life-threatening if not treated in time. However, a lesion of 4mm is usually an early stage of lung cancer, and the prognosis is better after treatment.
It is recommended that the patient should consult a specialist in time to analyze the possible causes of the disease and treat it with other test results.