0.4cm lung nodule can not be determined to belong to several grades, need to be based on the type of nodule, size, growth and other comprehensive assessment.
The RADS classification of lung nodules, which is the standard for evaluating the degree of malignancy of a nodule, needs to be based on multiple factors such as the type of nodule, its size, and its growth. It is not possible to determine the grade of a 0.4 cm lung nodule.
If the diameter of the solid lung nodule is less than 0.5cm, consider the low-risk nodule of lung cancer, and recommend follow-up after one year, this can be included in the RADS grading grade 2.
If the lung nodule is not uniform in density, although it is less than 0.5cm, it is still an intermediate risk and does not fall into the grade 2 criteria.
Therefore, if you find a lung nodule of 0.4cm, it is recommended to go to the hospital and let the doctor further clarify the diagnosis.