Comparison of histology between recurrent tonsillitis and tonsillar hypertrophy.

To elucidate the aetiology of tonsillar hypertrophy and recurrent tonsillitis, it is important to determine whether a difference exists between these two conditions in microanatomical architecture. The aim of this study was to investigate the difference in follicle size and numbers in tonsils for patients with tonsillar hypertrophy and recurrent tonsillitis using an image analysis method. Our results showed that there was no significant difference in the mean follicle numbers per counting field (40x magnification) between recurrent tonsillitis (4.5 +/- 2.1) and tonsillar hypertrophy (3.8 +/- 0.5). However, the mean follicle area in the tonsillar hypertrophy group (0.23 +/- 0.02 mm2) is significantly (P < 0.01) larger than in the recurrent tonsillitis group (0.15 +/- 0.02 mm2). Our study demonstrates that tonsillar hypertrophy is characterized histologically by an enlargement of follicles compared with chronic tonsillitis, indicating a hyperplastic condition of lymphoid cells in the germinal centres. It may also explain the difference in aetiology and/or immune defence mechanism underlying these two conditions.