Histopathological examinations of nasal polyps of different etiology

Summary A safe differentiation between allergic and non-allergic polyps appears impossible by means of light or electron microscopical examination of polyp tissue. There are some indications, however, which point to the allergic or non-allergic origin and it seems that the relationship between eosinophils and plasma cells with a low index is characteristic for polyps of allergic origin.Eosinophils and round-cell infiltrations are present in all types of polyps. An index of eosinophils to plasma cells below 5 is indicative for allergy and should induce the pathologist to give a hint to the clinician for allergological work-up. An index above 5 is more corresponding with infective etiology.Any changes of the basement membrane, i.e., smaller or larger gaps or even absence, are found only very irregularly and are not typical findings in either way.An increased number of glands and collagenic fibres, especially under the epithelium, are more an expression of the age of the polyp.Since the conservative therapy as mentioned above leads to good therapeutical results, it is desirable that an allergological work-up should be done in any case which shows the histological findings indicative for allergic etiology. Thus, repeated operations with all the risks and uncertain therapeutical benefit can be avoided.