Morphological characterization of the false vocal cords as larynx-associated lymphoid tissue

The lymphoid follicles (LF) found in the false vocal cords (FVC) protect the upper air tracts, similar to the lymphoid tissue associated to the respiratory mucosas. However, studies that characterize the phenotype of cells like larynx-associated lymphoid tissue (LALT) are lacking. We analyzed the FVC of autopsied adults according to morphometric and immunohistochemical criteria and defined their possible role as LALT. We analyzed 249 FVC. Primary antibodies, CD68+ macrophages, CD20+, CD3+, and FDC+ were used for the evaluation of inflammatory cell phenotypes. In 40.6% of the cases, there was an inflammatory reaction. In 42.2% of the cases, LF were identified in the submucosa. In 17.3% of the cases, neither LF nor mononuclear cells were identified in the FVC, and these patients were from an older age group (p=0.013). A significant increase in the number of all LF cell phenotypes was observed in patients with pulmonary inflammation; the difference in both T- and B-lymphocytes was statistically significant (p=0.010). The morphological findings of LF suggest a probable participation of the FVC in the protection of the larynx and lungs, and similarity to LALT.