Neoplasms of the parotid gland in northern Poland, 1991-2000: an epidemiologic study.

A review of patients treated for malignant and benign parotid tumors in a 10-year period (1991-2000) in the Pomeranian County of Poland revealed 417 new cases. The age-standardized incidence rate was 0.23 and 1.35 per 100,000 inhabitants for malignant and benign tumors, respectively. The following data were collected: age, sex, place of living, education, job, smoking, symptoms, duration of symptoms at the time of diagnosis, result of histopathological tumor examination, tumor size, TNM staging and distant metastases. The results were divided into two parts: malignant neoplasms and benign neoplasms. The most common malignant neoplasms were carcinomas (96.8%), and among them the most numerous were mucoepidermoid carcinoma (22.2%), carcinoma in pleomorphic adenoma (20.6%) and adenoid cystic carcinoma (15.9%). The most common benign neoplasms were adenomas (95.5%), most frequently pleomorphic adenoma (65.5%) and adenolymphoma (24.0%), but rarely basal cell adenoma (4.2%). We also observed a steady increase in the number of benign parotid tumors in the examined period of time.