SEROUS OTITIS MEDIA

    Histopathologically, serous otitis media is characterized by the presence of a thin effusion with no or few inflammatory cells.  The effusion is considered to be the product of a vascular transudate and can be accompanied by edema of the subepithelial layer.  Epithelial changes at this stage are minimal.  The etiology of this type of effusion is commonly Eustachian tube dysfunction, but it may also be seen in cases of primary or metastatic cancer of the tympanic cavity, or after a prolonged period on a respirator.  The following is an example of serous otitis media.