Actinomycosis in the etiology of recurrent tonsillitis and obstructive tonsillar hypertrophy: answer from a histopathologic point of view.

Objective: To investigate the histopathologic profile and clinical presentation of tonsillar disease in the presence of Actinomycetes in children.

Design: A qualitative and quantitative histopathologic analysis of the palatine tonsil was performed.

Setting: Tonsillectomy specimens from patients who underwent tonsillectomy or adenotonsillectomy were searched for Actinomycetes.

Methods: Histologic evaluation of the specimens was done on hematoxylin and eosin-stained slides as blinded to patients' clinical category for disease groups.

Main Outcome Measures: Four histologic compartments of the tonsil, including the surface epithelium, reticulated crypt epithelium (lymphoepithelium), lymphoid tissue, and interfollicular region, were examined.

Results: Actinomycetes was more prevalent in patients with obstructive symptoms treated with adenotonsillectomy. The number of subjectively quantitated total lymphoid follicles and small and medium-sized lymphoid follicles of the palatine tonsil were significantly increased in patients demonstrating "sulphur granules" in their crypts. Highly thick squamous metaplasia of the lymphoepithelium and dilatation of crypts were more prevalent in tonsil tissue revealing Actinomycetes.

Conclusions: The presence of Actinomycetes in tonsillectomy specimens does not indicate active tissue infection. However, the histopathologic outcome may indicate the possible etiologic role of Actinomycetes in the development of prominent lymphoid hyperplasia and hypertrophy and, in turn, obstructive tonsillar hypertrophy.