[Histological study of human lingual tonsil, especially changes with aging]

The lingual tonsils, in company with the pharyngeal and palatine tonsils, constitute Waldyer's tonsillar ring and function as an immunological organ. However, fewer reports have been published on the lingual tonsil than on the other tonsils. It can hardly be said that changes is the lingual tonsil related to age have been studied in detail. The author reported a qualitative study on both gross and histological findings of the lingual tonsil, focusing on its changes with aging, in 204 autopsied cases (124 males and 60 females). The results of the qualitative observations obtained were as follows: 1. The lingual tonsils were classified into three shapes based on gross findings; flat, prominent and hypertrophic. Most of the hypertrophic tonsils were seen in the group in the 2nd decade and in those aged between the 4th and 6th decade of life. 2. Lymphatic tissues were classified into three types; isolated diffuse, adhesive converged and independent converged types. It was presumed that reconstruction of the lymphatic tissue should occur independently of proliferation of the connective tissue since the lymphatic tissues of the three were not related to aging. 3. Hyperplasia of the connective tissue, which separated the lymphatic tissues, started in the 2nd decade and rapidly increased after the 6th decade. Hyperplasia of the elastic fiber in the capsula also started in the 2nd decade and increased with aging. The results of quantitative observation were as follows: 1. Total area of the lingual tonsil and lymphatic tissues in each slice of the specimen showed two peaks in size in the 2nd and 5th decades. 2. Total sum of the lymphfolliculus had changed with aging in the same manner as mentioned above in "1". The ratios of the lymphfolliculus to the parenchymal tissue and to the lymphepithelial symbiosis had also altered with aging. However, the number of lymphfolliculi per unit was almost constant. A significant difference between the sexes was detected below the 4th decade, when hormonal sexual difference were manifest. 3. Total sum of the area of the crypt increased from the 4th decade onward. From these findings, it is concluded that the lingual tonsil transiently responds to aging from the first to the 2nd decade, when the pharyngeal and palatine tonsils have dominant functions, and becomes active from the 4th to 5th decades, followed by a decrease in function after the 6th decade though its activity persists in elderly individuals.