Cholesterol content in middle ear fluid in secretory otitis media

The total cholesterol content was determined in 36 mucoid and 2 serous middle ear fluid samples (MEF). The hemoglobin was measured in all samples and the cholesterol value representing blood contamination was subtracted from the total cholesterol content of the sample. The values of the remaining cholesterol ranged from 0.1 to 4.7 mg/ml with a mean of 1.8. No correlation was found between cholesterol content and the size of the fluid sample. Nor was cholesterol content related to the status of mastoid pneumatization or clouding of the air cells. The presence of cholesterol in MEF is probably explained by seepage from the capillaries during the negative pressure phase and, in mucus-filled ears with no negative pressure, by disintegration of white blood cells in the fluid.