Solitary bronchial papilloma:a clinicopathological study of four cases and review of literature

Purpose To explore the clinicopathological features,differential diagnosis of solitary bronchial papilloma,and its relation with and human papilloma virus infection.Methods Four cases of SBP were studied by routine histologic,immunohistochemical staining and in situ hybridization,together with review of the literature.Results One of four lesions was squamous cell papilloma,with focal malignant change of squamous cell carcinoma with microinvasion.The case was an old woman and the cancer located in central bronchus.Others were mixed squamous cell and glandular papilloma,and two cases with features of moderate cytologic atypia.The age ranged from 25 to 73 years (average 54),and tumors were located in the bronchi and segmental bronchi.Papillary arborizing connective tissue stalks were lined by both squamous and glandular epithelium.Four papillomas were exophytic,with one case inverted partly.Four cases were examined for HPV DNA and all were negative.Conclusions SBP in adults is a rare lung neoplasm.Based on uncommon cases association with malignant change,all endobronchial papillomas should be completely excised.