Abstract: Objective To investigate risk factors of the malignant space-occupying disease with benign computed tomography (CT) graph on upper lobe-back segment of lung, so as to provide theoretic basis for clinical diagnosis. Methods Retrospective study of the 139 patients with the malignant space-occupying disease with benign CT graph on upper lobe-back segment of lung,from Department of Thoracic Surgery, Xuanwu hospital, Capital Medical University and Department of Thoracic Surgery, Pinggu Hospital, Friendship Hospital, Capital Medical University, from January 1, 2011 to December 31st, 2016. The incidence rates of each year were calculated. We compared the clinical data of patients and used Logistic regression to analyze the risk factors in our study. Results Incidence rates of the malignant space-occupying disease with benign CT graph on upper lobe-back segment of lung in each year were 8.33%, 11.11%, 19.05%, 26.92%, 34.38%, 40.00% respectively. Logistic regression showed the risk factors OR (95%CI) of the malignant space-occupying disease with benign CT graphy on upper lobe-back segment of lung were: ages 1.123(1.038-1.215), smoking 5.951(1.778-9.919), right space-occupying diseases 3.547(1.104-10.397), positive single-photon emission computed tomography (SPECT) agglomeration 3.565(1.096-11.598), abnormal related marks of lung cancer ［carcino-embryonic antigen (CEA), cytokeratin protein fragment 21-1 (CYFRA21-1), neuron specific enolase (NSE)］ 18.638 (4.974-29.843), 7.357(2.265-13.010), 7.639(3.107-14.697). Conclusion The incidence rates of the malignant space-occupying disease with benign CT graph on upper lobe-back segment of lung in each year were high, and doctors should pay more attentions to considerate risk factors such as ages, smoking, right space-occupying diseases, positive SPECT agglomeration as well as abnormal related marks of lung cancer when they diagnose. Early detection and early treatment can improve the survival of patients.

Key words: space-occupying on upper lobe-back segment of lung, computed tomography graph, risk factors