Increasing prevalence of papillary thyroid carcinoma in recent years in Greece: the majority are incidental.

BACKGROUND: New cases of well-differentiated thyroid cancer (DTC) are diagnosed more frequently worldwide. We investigated trends and differences in clinical and histological characteristics of new DTC cases presenting in one large center. METHODS: During the last 34 years 852 follicular cell-derived DTC cases (83% papillary [PTC], 17% follicular [FTC] carcinoma) presented in the Endocrine Unit of the Department of Clinical Therapeutics in Alexandra Hospital (18.8% men, mean age 42.4 +/- 14.5 years). Patients were classified in three period groups according to year of diagnosis: period 1, 1963-1982; period 2, 1983-1992; and period 3, 1993-2007. We recorded the histological type, age at diagnosis, and, in period 3, the type of pre-existing thyroid disease, the stage, and tumor size. RESULTS: During periods 1, 2, and 3, the mean age at diagnosis was 37.7 +/- 12.3, 42.4 +/- 14.53, and 44.1 +/- 14.9 years (p = 0.001), respectively, and the male to female ratio was similar. The prevalence of FTC was 22.7%, 28.1%, and 6.5%, respectively. In period 3, 51.6% of the PTCs were microcarcinomas (microPTC)