Abstract:

Objective To retrospectively analyze the CT features of lung cancers associated with cystic airspaces and cavitary pulmonary tuberculosis, and to improve the diagnosis and differential diagnosis.Methods Twenty-three cases with lung cancer associated with cystic airspaces who were admitted to Affiliated Zhongshan Hospital of Dalian University and confirmed by surgery and/or biopsy between March 2015 and May 2018 were collected as lung cancer group. In the same period, 31 cases of cavitary tuberculosis confirmed by laboratory bacteriological examination and clinical follow-up or treatment from Tuberculosis Hospital of Dalian were selected as tuberculosis group. The CT data of the patients were collected and the CT feature were compared between two groups.Results Most of the lesions were located in the right lung (lung cancer group: 60.9% (14/23); tuberculosis group: 61.3% (19/31)). The lesion size of lung cancer group was smaller than that of the tuberculosis group ((17.19±11.02) mm vs (27.13±10.42) mm), and the difference was statistically significant (t=-2.55, P=0.014). The average thickness of cavity wall of the lung cancer group ((1.91±0.73) mm) was smaller than that of the tuberculosis group ((2.69±0.47) mm), and the difference was statistically significant (t=3.05, P<0.05). The rate of patients with wall nodules in the cystic cavity in the lung cancer group (47.8%, 11/23) was higher than that in the tuberculosis group (19.4%, 6/31), and the difference was statistically significant (χ ²=7.69, P<0.05). In the lung cancer group, shadow of the vascular branch in the cystic cavity was shown in 43.5% (10/23) of the patients, but no vascular branch shadow appeared in the cavity of the tuberculosis group. The difference was statistically significant (χ ²=11.71, P<0.01). In the lung cancer group, 5 patients (21.7%) had lobular stenosis at the edge of the cyst, and 13 patients (56.5%) had burr marks. In the tuberculosis group, the lobes were visible at the margin of the cavity in 6 patients (19.4%), and 16 patients (51.6%) had burr sign. The difference was not statistically significant (χ ²=0.61, P>0.05). Among the patients in the lung cancer group, 12 patients (52.2%) had pleural indentation, and 23 patients (74.2%) in the tuberculosis group had different degrees of adjacent pleural thickening. The difference was statistically significant (χ ²=11.04, P<0.05). Conclusion CT findings of lung cancers associated with cystic airspaces are characteristic. Typical CT features can help us make a suggestive diagnosis of this type of lung cancer, and help to differential diagnosis from cavitary tuberculosis.

Key words: Lung neoplasms, Tuberculosis, pulmonary, Tomography, X-ray computed, Diagnosis, differential