Ultrastructural morphology of mucoid effusion in secretory otitis media.

The ultrastructural morphology of 19 mucoid middle ear effusions in 14 children with secretory otitis media was studied. Phagocytosing neutrophil granulocytes were the most common inflammatory cells, and ingested bacteria were present in some of them. The next in frequency were macrophages and lymphocytes. Monocytes and polyblasts were also present in most specimens. No plasma cells, eosinophil granulocytes or mast cells were seen. Epithelial cells were common, and great numbers of free and phagocytosed mucus granules were found. Considerable numbers of all the celltypes were in various stages of disintegration. Thus, it seems that the effusion in secretory otitis media is primarily of inflammatory origin, and the dissolution of the cells with liberated cellular contents, together with the secretion of the mucosa, contributes to the formation of the effusion.