A 1.1cm lung nodule may be caused by inflammation, by benign neoplastic disease such as an eruption of an erratic tumor, or by a malignant tumor such as lung cancer. There are many causes of 1.1cm pulmonary nodules on imaging in the lungs, and the possible etiologies need to be comprehensively determined based on the size, shape, composition, and presence or absence of calcifications or burrs. It may be caused by infectious lesions such as Mycobacterium tuberculosis or fungal infections; benign tumors such as fibromas and malignant tumors; or malignant tumors such as lung cancer. If a 1.1cm pulmonary nodule is found in the lung, patients are advised to consult a specialist for further examination and treatment as prescribed by the doctor.