CT Signs and Differential Diagnosis of Peripheral Lung Cancer and Inflammatory Pseudotumor: A Meta-Analysis

We aimed to systematically evaluate the imaging features of peripheral lung cancer and inflammatory pseudotumor. PubMed, Embase, Cochrane Library, Chinese Knowledge Infrastructure (CNKI), Wanfang database (Wanfang), and Chinese Biomedical Network (CBM) were searched to collect relevant studies on CT image comparison of peripheral lung cancer and inflammatory pseudotumor. The search time was from database establishment to July 15, 2021. The search language was limited to Chinese and English. Data from the literature were screened and extracted, and meta-analysis was performed using Stata 16.0 software. A total of 8 cohort studies were included in this meta-analysis, including 675 patients. Meta-analysis showed that the lesion size of inflammatory pseudotumor was greater than that of peripheral lung cancer, and the difference had statistical significance [SMD = 0.29, 95% CI (0.01, 0.58), P < 0.05]. The difference in HU value between inflammatory pseudotumor and peripheral lung cancer CT had no statistical significance [SMD = -0.09, 95% CI (-0.79, 0.60), P > 0.05]. The HU value of enhanced CT of inflammatory pseudotumor was higher than that of peripheral lung cancer, and the difference had statistical significance [SMD = 0.75, 95% CI (0.15, 1.34), P < 0.05]. The incidence of calcification of inflammatory pseudotumor was significantly higher than that of peripheral lung cancer, and the difference had statistical significance [RR = 2.85, 95% CI (1.33, 6.11), P < 0.05]. The incidence of long hair puncture sign of inflammatory pseudotumor was lower than that of peripheral lung cancer, and the difference had statistical significance [RR = 0.49, 95% CI (0.24, 0.97), P < 0.05]. There was no significant difference between inflammatory pseudotumor and peripheral lung cancer in terms of cavity incidence, vacuole sign, pleural indentation, and bronchial inflation sign (P > 0.05). Based on the available literature evidence, it can be found that there are differences in the CT signs between peripheral lung cancer and inflammatory pseudotumor, and the lesion size, HU value on enhanced CT, incidence of calcification, and incidence of burr sign may be important indicators for differentiating peripheral lung cancer from inflammatory pseudotumor.