Local inflammatory reaction to benign, pre‐malignant and malignant glottic lesions: A matched case‐control study

Objectives To study the inflammatory infiltrates associated with the different stages of laryngeal carcinogenesis. Design Observational, matched case‐control study of histopathologic specimens. Setting An academic referral centre. Participants A total of 45 patients who underwent removal of glottic lesions between 2008 and 2015. Patients were enrolled and categorised into three matched groups according to lesions' histopathologic diagnoses, 15 patients in each group: benign, pre‐malignant and squamous cell carcinoma (SCC). Matching was based on age, gender and pack‐years. Main outcome measures Immunohistochemistry staining using monoclonal antibodies against CD4, CD8, CD68, CD20 and S100 representing T‐helper cells, cytotoxic T cells, macrophages, B cells and dendritic cells, respectively. Cell counts and distributions were measured and compared between groups. Correlations between the different cells were examined. Results The predominant cell type was CD8+, followed by CD68+ and CD4+. All inflammatory cells increased significantly in number in SCC (P‐value