Clinicopathological Features, Surgical Outcomes, Oncogenic Status and PD-L1 Expression of Pulmonary Pleomorphic Carcinoma

Background/Aim: Pulmonary pleomorphic carcinoma (PPC) is rare, and few studies have reported its features. We assessed the clinicopathological features, surgical outcomes, oncogenic status and programmed death-ligand 1 (PD-L1) expression of PPC. Patients and Methods: We retrospectively reviewed data from 22 consecutive patients who underwent resection of PPC between 2007 and 2017. Results: The predominant tissue type of the epithelial component was adenocarcinoma in 15 patients (68%) and the others in 7 patients (32%), and the 3-year disease-free survival rate tended to be better in patients with an adenocarcinoma component compared to patients with another component (40.0% vs. 17.1%, p=0.059). PD-L1 expression was observed in all eight tumors whose PD-L1 status could be examined and high PD-L1 expression (>= 50%) was frequent (5/8, 63%). Conclusion: A predominant adenocarcinoma epithelial component in PPC might be associated with better survival outcomes and high PD-L1 expression might be frequent in PPC.