Lobulated mass with small cavity in the dorsal segment of the lower lobe of the right lung is the result of chest CT examination, which may be caused by lung cancer, tuberculosis or lung abscess. 1. Lung cancer: lung cancer is a kind of primary malignant tumor originated from lung, which can lead to the appearance of lobulated mass in the dorsal segment of the lower lobe of the right lung, accompanied by small cavities in the CT, and the patient can also have other symptoms such as cough and blood in sputum. 2. Tuberculosis: Tuberculosis is a kind of lung disease caused by Mycobacterium tuberculosis infection, patients with this disease can also appear in the CT of the lower lobe of the right lung dorsal lobe mass, accompanied by small cavities in the manifestation of the patient can also appear cough, cough sputum, hemoptysis, fever, fatigue, night sweats and other symptoms. 3. Lung abscess: lung abscess is a kind of disease caused by infection leading to necrosis of lung tissue and formation of pus cavity, which can lead to the appearance of lobulated swelling in the dorsal segment of the lower lobe of the right lung with small cavities under CT, and the patient will also have symptoms such as high fever, chills, cough, sputum, chest pain. If CT examination reveals a lobulated mass with a small cavity in the dorsal segment of the lower lobe of the right lung, it is recommended to consult a doctor to find out the cause of the mass and ask the doctor to take care of it.