Tumours in Iceland. 4. Tumours of the upper respiratory tract and ear. A histological classification and some etiological and epidemiological considerations.

All primary tumours from the upper respiratory tract and ear submitted for a histological diagnosis in Iceland during the 20 years, 1955-1974, were reviewed and typed according to the World Health Organization Classification published in 1978. The series included 83 benign and 114 malignant tumours from the upper respiratory tract. The nasal cavity was the commonest site for benign tumours in both sexes, most being squamous cell and transitional papillomas. The larynx was the commonest site for malignant tumours in males, all being squamous cell carcinomas, and the paranasal sinuses and the nasopharynx in females, squamous cell carcinoma forming the largest group in the sinuses and undifferentiated carcinoma in the nasopharynx. The distribution of tumours in the nasal cavity and sinuses differed much between the two sites and between the sexes, which emphasizes that these two sites should be separated and not combined as they have been until recently in epidemiological reports and cancer registries. A relatively high incidence of nasopharyngeal carcinoma in Iceland may be due to a high consumption of salted food. A rising incidence of laryngeal carcinoma is believed to be related to the use of tobacco and alcohol and is of special concern owing to its marked rise in young females.