Features And Differential Diagnosis Of Peripheral Lung Cancer And Pulmonary Tuberculoma In The CT Images

Part 1 Evaluation of the diagnostic values of lobulation sign on the differential diagnosis of peripheral lung cancer and pulmonary tuberculoma in CT images.Objective :To assess the overall value of lobulation sign and deep lobulation sign in the differential diagnosis of peripheral lung cancer and pulmonary tuberculoma in CT images.Methods : Firstly , articles about CT differential diagnosis between pulmonary tuberculoma and peripheral lung cancer were selected ,which were published in the period(from January 1990 to December 2008),and useful data were extracted.Then Meta-analysis was done using Meta-disc software,and SDOR value calculated. Subsequently,pooled weighted sensitivity,specificity,positive likelihood ratio and negative likelihood ratio were analyzed . Finally , summary receiver operating characteristic curve was drawn.Results : Ten articles about lobulation sign were included,with 9 independent researches and a total of 747 subjects(including 495 cases of peripheral lung cancer and 252 cases of pulmonary tuberculoma). And there were 4 articles about deep lobulation sign with 289 patients. Heterogeneity existed. The pooled sensitivity value was 0.78 and 0.50 ,respectively;the pooled specificity value was 0.82 and 0.94,respectively;the pooled positive likelihood ratio was 3.42 and 6.22,respectively;and the pooled negative likelihood ratio was 0.31 and 0.56,respectively. The area under the SROC curved was 0.859 and 0.822, respectively.The SDOR value of lobulation and deep lobulation in diagnosing peripheral pulmonary carcinoma was 14.2 and 13.1,respectively.Conclusion:Lobulation sign has a certain specificity and high sensitivity in the CT differential diagnosis of peripheral lung cancer and tuberculoma. Deep lobulation for the diagnosis of peripheral lung cancer less sensitive, but higher specificity. Part 2 Features and differential diagnosis of peripheral lung cancer and pulmonary tuberculoma in the CT imagesObjective: to discuss features of peripheral lung cancer and pulmonary tuberculoma in the CT images, and improve our knowledge about the two diseases.Methods: 165 cases (male 103 cases and female 62 cases) of pulmonary globular space-occupying lesions from Jan. 2005 to Jan. 2009 were included in the study, of which 60 pulmonary tuberculoma cases (6 multiple cases with 8 lesions) and 105 solitary peripheral lung cancer cases. And all the 173 lesions enrolled in the study were confirmed by surgery, bronchoscopy or needle biopsy. A retrospective study of the CT images of the pulmonary tuberculoma and peripheral lung cancer lesions was made and the common morphological features were statistically analyzed with SPSS software.Results: First, the general conditions of cases enrolled were described and registered. Among the 173 lesions, 85 lesions (43 peripheral lung cancer cases and 42 pulmonary tuberculoma cases) presented as pulmonary nodules (max diameter less than 3cm), and the remaining lesions presented as neoplasms. Then, the common features of the peripheral lung cancer and pulmonary tuberculoma were outlined. In the peripheral lung cancer group, 83 cases presented with lobulation sign, among which 61 lesions had deep lobulation signs. And speculation sign presented in 76 cases, halo sign in 14 cases, vacuole sign in 17 cases, intra-lesional cavity with thick wall in 11 cases, spot-like calcification in 7 cases, pleural indentation in 58 cases, and bronchus sign in 77 cases. In the pulmonary tuberculoma group, 28 cases presented with lobulation sign, among which 9 lesions had deep lobulation signs. And speculation sign presented in 13 cases, halo sign in 10 cases, vacuole sign in 2 cases, intra-lesional cavity in 24 cases (4 cases with thin cavity wall), different forms of calcifications in 15 cases, pleural indentation in 19 cases, and bronchus sign in 38 cases. Finally, the features of the lesions were statistically analyzed. There were significant differences in lobulation sign, deep lobulation sign, speculation sign, vacuole sign, pleural indentation and bronchus sign between the two groups(P<0.05). Cavities and calcifications were more common in the pulmonary tuberculoma group(P<0.05). The incidence of thick wall cavity had no significant difference between the two groups. And halo sign had a very low incidence rate in both groups and no intergroup difference was observed. Further screening was conducted with logistic regression analysis (OR value of the 95% CI of the deep lobulation signs and speculation sign >1), which indicates the tendancy of deep lobulation signs and speculation sign towards lung cancer and the tendancy of calcification and cavity towards pulmonary tuberculoma.Conclusion: Signs of peripheral lung cancer and pulmonary tuberculoma can be clearly visualized in CT images. Although overlay of the signs are common, there are difference in the detail features of the signs, which make them an important evidence for the differential diagnosis of the two diseases. the value of a single sign in the differential diagnosis between peripheral lung cancer and pulmonary tuberculoma is limited and multi-signs analysis in the differential diagnosis process tends to achieve the correct conclusion.