Benign features of infection-related tumor-like lesions of the lung: A retrospective imaging review study

Introduction: Differentiation of benign and malignant pulmonary tumor-like lesions is challenging but increasingly important. We evaluate the most common imaging features in benign lesions based on the frequency of their appearance and compare with corresponding frequencies in malignant tumors from literature. Methods: Retrospective imaging review study in one center between 1 January 2012 and 30 June 2014. We reviewed the data from 2466 pathological examinations of lung specimens collected from the hospital. We excluded malignant or non-tumor-like lesions and identified 133 infection-related lesions for imaging review. The frequency of 11 benign imaging features was evaluated in the selected infection-related tumor-like pulmonary lesions and was compared with corresponding frequency in malignant tumors. Results: Most of the evaluated lesions were seen to have one to four benign features. The two most common benign features are marginal ground glass or infiltrates (62.4%), followed by pleura-based wedge shape (50.4%). Features with significantly higher frequency in benign infection-related lung lesions than malignancy are calcification or hyperdensity, pleura-based wedge shape, adjacent clustered small nodules, and strongly or poorly enhanced soft tissue part. Conclusions: Infection-related lung lesions usually have one to four benign features and the common features with significantly higher frequency than malignant condition are pleura-based wedge shape, calcification or hyperdensity, adjacent clustered small nodules, and strongly or poorly enhanced soft tissue part.