Comparison of CT findings between basaloid squamous cell carcinoma and non-basaloid squamous cell carcinoma of the lung

Background: To compare computed tomography (CT) findings between basaloid lung squamous cell carcinoma (SCC) and non-basaloid SCC. Methods: From July 2003 to April 2021, 39 patients with surgically proven basaloid SCC were identified. For comparison, 161 patients with surgically proven non-basaloid SCC from June 2018 to January 2019 were selected consecutively. Clinical features, demographic characteristics, and CT findings were compared using chi-square test or Fisher’s exact test except for differences in means for which Student’s t -test was used. Additionally, Mantel-Haenszel test was performed to control the confounding of the presence of cavitation between basaloid and non-basaloid SCCs with tumors stratified by clinical T staging. Results: Compared with patients with non-basaloid SCC, patients with basaloid SCC had significantly ( P< 0.001) more frequent respiratory symptoms at the time of presentation. Regarding CT findings, endobronchial tumor growth and obstructive pneumonia or atelectasis were significantly ( P= 0.028) more common in basaloid SCC than in non-basaloid SCC. Compared with non-basaloid SCC, cavitation was absent ( P= 0.005) and internal profuse necrosis was significantly ( P= 0.022) less frequent in basaloid SCC. Furthermore, presence of cavitation consistently showed significant difference after the tumors stratified based on clinical T staging ( P= 0.015). Conclusion: Basaloid SCC had some CT findings different from non-basaloid SCC. Basaloid SCC showed more frequent endobronchial tumor growth with obstructive pneumonia or atelectasis. Internal profuse necrosis was less common, and cavitation was absent in basaloid SCC compared to non-basaloid SCC.